fbpx
Wikipedia

Integrin

Integrins are transmembrane receptors that help cell-cell and cell-extracellular matrix (ECM) adhesion.[3] Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, organization of the intracellular cytoskeleton, and movement of new receptors to the cell membrane.[4] The presence of integrins allows rapid and flexible responses to events at the cell surface (e.g. signal platelets to initiate an interaction with coagulation factors).

Integrin alphaVbeta3 extracellular domains
Structure of the extracellular segment of integrin alpha Vbeta3.[1]
Identifiers
SymbolIntegrin_alphaVbeta3
PfamPF08441
Pfam clanCL0159
InterProIPR013649
SCOP21jv2 / SCOPe / SUPFAM
OPM superfamily176
OPM protein2knc
Membranome13
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary
Integrin alpha cytoplasmic region
Structure of chaperone protein PAPD.[2]
Identifiers
SymbolIntegrin_alpha
PfamPF00357
InterProIPR000413
PROSITEPDOC00215
SCOP21dpk / SCOPe / SUPFAM
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary
Integrin, beta chain (vWA)
Identifiers
SymbolIntegrin_beta
PfamPF00362
InterProIPR002369
SMARTSM00187
PROSITEPDOC00216
SCOP21jv2 / SCOPe / SUPFAM
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary
PDB1jv2​, 1kup​, 1kuz​, 1l3y​, 1l5g​, 1m1x​, 1m8o​, 1s4x​, 1txv​, 1ty3​, 1ty5​, 1ty6​, 1ty7​, 1tye​, 1u8c
Integrin beta 7 cytoplasmic domain: complex with filamin
crystal structure of the filamin a repeat 21 complexed with the integrin beta7 cytoplasmic tail peptide
Identifiers
SymbolIntegrin_b_cyt
PfamPF08725
InterProIPR014836
SCOP21m8O / SCOPe / SUPFAM
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary

Several types of integrins exist, and one cell generally has multiple different types on its surface. Integrins are found in all animals while integrin-like receptors are found in plant cells.[3]

Integrins work alongside other proteins such as cadherins, the immunoglobulin superfamily cell adhesion molecules, selectins and syndecans, to mediate cell–cell and cell–matrix interaction. Ligands for integrins include fibronectin, vitronectin, collagen and laminin.

Structure edit

Integrins are obligate heterodimers composed of α and β subunits. Several genes code for multiple isoforms of these subunits, which gives rise to an array of unique integrins with varied activity. In mammals, integrins are assembled from eighteen α and eight β subunits,[5] in Drosophila five α and two β subunits, and in Caenorhabditis nematodes two α subunits and one β subunit.[6] The α and β subunits are both class I transmembrane proteins, so each penetrates the plasma membrane once, and can possess several cytoplasmic domains.[7]

alpha (mammal)
gene protein synonyms
ITGA1 CD49a VLA1
ITGA2 CD49b VLA2
ITGA3 CD49c VLA3
ITGA4 CD49d VLA4
ITGA5 CD49e VLA5
ITGA6 CD49f VLA6
ITGA7 ITGA7 FLJ25220
ITGA8 ITGA8
ITGA9 ITGA9 RLC
ITGA10 ITGA10 PRO827
ITGA11 ITGA11 HsT18964
ITGAD CD11D FLJ39841
ITGAE CD103 HUMINAE
ITGAL CD11a LFA1A
ITGAM CD11b MAC-1
ITGAV CD51 VNRA, MSK8
ITGA2B CD41 GPIIb
ITGAX CD11c
beta (mammal)
gene protein synonyms
ITGB1 CD29 FNRB, MSK12, MDF2
ITGB2 CD18 LFA-1, MAC-1, MFI7
ITGB3 CD61 GP3A, GPIIIa
ITGB4 CD104
ITGB5 ITGB5 FLJ26658
ITGB6 ITGB6
ITGB7 ITGB7
ITGB8 ITGB8

Variants of some subunits are formed by differential RNA splicing; for example, four variants of the beta-1 subunit exist. Through different combinations of the α and β subunits, 24 unique mammalian integrins are generated, excluding splice- and glycosylation variants.[8]

Integrin subunits span the cell membrane and have short cytoplasmic domains of 40–70 amino acids. The exception is the beta-4 subunit, which has a cytoplasmic domain of 1,088 amino acids, one of the largest of any membrane protein. Outside the cell membrane, the α and β chains lie close together along a length of about 23 nm; the final 5 nm N-termini of each chain forms a ligand-binding region for the ECM. They have been compared to lobster claws, although they don't actually "pinch" their ligand, they chemically interact with it at the insides of the "tips" of their "pinchers".

The molecular mass of the integrin subunits can vary from 90 kDa to 160 kDa. Beta subunits have four cysteine-rich repeated sequences. Both α and β subunits bind several divalent cations. The role of divalent cations in the α subunit is unknown, but may stabilize the folds of the protein. The cations in the β subunits are more interesting: they are directly involved in coordinating at least some of the ligands that integrins bind.

Integrins can be categorized in multiple ways. For example, some α chains have an additional structural element (or "domain") inserted toward the N-terminal, the alpha-A domain (so called because it has a similar structure to the A-domains found in the protein von Willebrand factor; it is also termed the α-I domain). Integrins carrying this domain either bind to collagens (e.g. integrins α1 β1, and α2 β1), or act as cell-cell adhesion molecules (integrins of the β2 family). This α-I domain is the binding site for ligands of such integrins. Those integrins that don't carry this inserted domain also have an A-domain in their ligand binding site, but this A-domain is found on the β subunit.

In both cases, the A-domains carry up to three divalent cation binding sites. One is permanently occupied in physiological concentrations of divalent cations, and carries either a calcium or magnesium ion, the principal divalent cations in blood at median concentrations of 1.4 mM (calcium) and 0.8 mM (magnesium). The other two sites become occupied by cations when ligands bind—at least for those ligands involving an acidic amino acid in their interaction sites. An acidic amino acid features in the integrin-interaction site of many ECM proteins, for example as part of the amino acid sequence Arginine-Glycine-Aspartic acid ("RGD" in the one-letter amino acid code).

Structure edit

Despite many years of effort, discovering the high-resolution structure of integrins proved to be challenging, as membrane proteins are classically difficult to purify, and as integrins are large, complex and highly glycosylated with many sugar 'trees' attached to them. Low-resolution images of detergent extracts of intact integrin GPIIbIIIa, obtained using electron microscopy, and even data from indirect techniques that investigate the solution properties of integrins using ultracentrifugation and light scattering, were combined with fragmentary high-resolution crystallographic or NMR data from single or paired domains of single integrin chains, and molecular models postulated for the rest of the chains.

The X-ray crystal structure obtained for the complete extracellular region of one integrin, αvβ3,[1] shows the molecule to be folded into an inverted V-shape that potentially brings the ligand-binding sites close to the cell membrane. Perhaps more importantly, the crystal structure was also obtained for the same integrin bound to a small ligand containing the RGD-sequence, the drug cilengitide.[9] As detailed above, this finally revealed why divalent cations (in the A-domains) are critical for RGD-ligand binding to integrins. The interaction of such sequences with integrins is believed to be a primary switch by which ECM exerts its effects on cell behaviour.

The structure poses many questions, especially regarding ligand binding and signal transduction. The ligand binding site is directed towards the C-terminal of the integrin, the region where the molecule emerges from the cell membrane. If it emerges orthogonally from the membrane, the ligand binding site would apparently be obstructed, especially as integrin ligands are typically massive and well cross-linked components of the ECM. In fact, little is known about the angle that membrane proteins subtend to the plane of the membrane; this is a problem difficult to address with available technologies. The default assumption is that they emerge rather like little lollipops, but there is little evidence for this. The integrin structure has drawn attention to this problem, which may have general implications for how membrane proteins work. It appears that the integrin transmembrane helices are tilted (see "Activation" below), which hints that the extracellular chains may also not be orthogonal with respect to the membrane surface.

Although the crystal structure changed surprisingly little after binding to cilengitide, the current hypothesis is that integrin function involves changes in shape to move the ligand-binding site into a more accessible position, away from the cell surface, and this shape change also triggers intracellular signaling. There is a wide body of cell-biological and biochemical literature that supports this view. Perhaps the most convincing evidence involves the use of antibodies that only recognize integrins when they have bound to their ligands, or are activated. As the "footprint" that an antibody makes on its binding target is roughly a circle about 3 nm in diameter, the resolution of this technique is low. Nevertheless, these so-called LIBS (Ligand-Induced-Binding-Sites) antibodies unequivocally show that dramatic changes in integrin shape routinely occur. However, how the changes detected with antibodies look on the structure is still unknown.

Activation edit

When released into the cell membrane, newly synthesized integrin dimers are speculated to be found in the same "bent" conformation revealed by the structural studies described above. One school of thought claims that this bent form prevents them from interacting with their ligands, although bent forms can predominate in high-resolution EM structures of integrin bound to an ECM ligand. Therefore, at least in biochemical experiments, integrin dimers must apparently not be 'unbent' in order to prime them and allow their binding to the ECM. In cells, the priming is accomplished by a protein talin, which binds to the β tail of the integrin dimer and changes its conformation.[10][11] The α and β integrin chains are both class-I transmembrane proteins: they pass the plasma membrane as single transmembrane alpha-helices. Unfortunately, the helices are too long, and recent studies suggest that, for integrin gpIIbIIIa, they are tilted with respect both to one another and to the plane of the membrane. Talin binding alters the angle of tilt of the β3 chain transmembrane helix in model systems and this may reflect a stage in the process of inside-out signalling which primes integrins.[12] Moreover, talin proteins are able to dimerize[13] and thus are thought to intervene in the clustering of integrin dimers which leads to the formation of a focal adhesion. Recently, the Kindlin-1 and Kindlin-2 proteins have also been found to interact with integrin and activate it.[14]

Function edit

Integrins have two main functions, attachment of the cells to the ECM and signal transduction from the ECM to the cells.[15] They are also involved in a wide range of other biological activities, including extravasation, cell-to-cell adhesion, cell migration, and as receptors for certain viruses, such as adenovirus, echovirus, hantavirus, foot-and-mouth disease, polio virus and other viruses. Recently, the importance of integrins in the progress of autoimmune disorders is also gaining attention of the scientists. These mechanoreceptors seem to regulate autoimmunity by dictating various intracellular pathways to control immune cell adhesion to endothelial cell layers followed by their trans-migration. This process might or might not be dependent on the sheer force faced by the extracellular parts of different integrins.[16]

A prominent function of the integrins is seen in the molecule GpIIb/IIIa, an integrin on the surface of blood platelets (thrombocytes) responsible for attachment to fibrin within a developing blood clot. This molecule dramatically increases its binding affinity for fibrin/fibrinogen through association of platelets with exposed collagens in the wound site. Upon association of platelets with collagen, GPIIb/IIIa changes shape, allowing it to bind to fibrin and other blood components to form the clot matrix and stop blood loss.

Attachment of cell to the ECM edit

Integrins couple the cell-extracellular matrix (ECM) outside a cell to the cytoskeleton (in particular, the microfilaments) inside the cell. Which ligand in the ECM the integrin can bind to is defined by which α and β subunits the integrin is made of. Among the ligands of integrins are fibronectin, vitronectin, collagen, and laminin. The connection between the cell and the ECM may help the cell to endure pulling forces without being ripped out of the ECM. The ability of a cell to create this kind of bond is also of vital importance in ontogeny.

Cell attachment to the ECM is a basic requirement to build a multicellular organism. Integrins are not simply hooks, but give the cell critical signals about the nature of its surroundings. Together with signals arising from receptors for soluble growth factors like VEGF, EGF, and many others, they enforce a cellular decision on what biological action to take, be it attachment, movement, death, or differentiation. Thus integrins lie at the heart of many cellular biological processes. The attachment of the cell takes place through formation of cell adhesion complexes, which consist of integrins and many cytoplasmic proteins, such as talin, vinculin, paxillin, and alpha-actinin. These act by regulating kinases such as FAK (focal adhesion kinase) and Src kinase family members to phosphorylate substrates such as p130CAS thereby recruiting signaling adaptors such as CRK. These adhesion complexes attach to the actin cytoskeleton. The integrins thus serve to link two networks across the plasma membrane: the extracellular ECM and the intracellular actin filamentous system. Integrin α6β4 is an exception: it links to the keratin intermediate filament system in epithelial cells.[17]

Focal adhesions are large molecular complexes, which are generated following interaction of integrins with ECM, then their clustering. The clusters likely provide sufficient intracellular binding sites to permit the formation of stable signaling complexes on the cytoplasmic side of the cell membrane. So the focal adhesions contain integrin ligand, integrin molecule, and associate plaque proteins. Binding is propelled by changes in free energy.[18] As previously stated, these complexes connect the extracellular matrix to actin bundles. Cryo-electron tomography reveals that the adhesion contains particles on the cell membrane with diameter of 25 +/- 5 nm and spaced at approximately 45 nm.[19] Treatment with Rho-kinase inhibitor Y-27632 reduces the size of the particle, and it is extremely mechanosensitive.[20]

One important function of integrins on cells in tissue culture is their role in cell migration. Cells adhere to a substrate through their integrins. During movement, the cell makes new attachments to the substrate at its front and concurrently releases those at its rear. When released from the substrate, integrin molecules are taken back into the cell by endocytosis; they are transported through the cell to its front by the endocytic cycle, where they are added back to the surface. In this way they are cycled for reuse, enabling the cell to make fresh attachments at its leading front.[21] The cycle of integrin endocytosis and recycling back to the cell surface is important also for not migrating cells and during animal development.[22]

Signal transduction edit

Integrins play an important role in cell signaling by modulating the cell signaling pathways of transmembrane protein kinases such as receptor tyrosine kinases (RTK). While the interaction between integrin and receptor tyrosine kinases originally was thought of as uni-directional and supportive, recent studies indicate that integrins have additional, multi-faceted roles in cell signaling. Integrins can regulate the receptor tyrosine kinase signaling by recruiting specific adaptors to the plasma membrane. For example, β1c integrin recruits Gab1/Shp2 and presents Shp2 to IGF1R, resulting in dephosphorylation of the receptor.[23] In a reverse direction, when a receptor tyrosine kinase is activated, integrins co-localise at focal adhesion with the receptor tyrosine kinases and their associated signaling molecules.

The repertoire of integrins expressed on a particular cell can specify the signaling pathway due to the differential binding affinity of ECM ligands for the integrins. The tissue stiffness and matrix composition can initiate specific signaling pathways regulating cell behavior. Clustering and activation of the integrins/actin complexes strengthen the focal adhesion interaction and initiate the framework for cell signaling through assembly of adhesomes.[24]

Depending on the integrin's regulatory impact on specific receptor tyrosine kinases, the cell can experience:

Knowledge of the relationship between integrins and receptor tyrosine kinase has laid a foundation for new approaches to cancer therapy. Specifically, targeting integrins associated with RTKs is an emerging approach for inhibiting angiogenesis.[26]

 
Integrins are localised at the growth cone of regenerating neurons.[27]

Integrins and nerve repair edit

Integrins have an important function in neuroregeneration after injury of the peripheral nervous system (PNS).[27] Integrins are present at the growth cone of damaged PNS neurons and attach to ligands in the ECM to promote axon regeneration. It is unclear whether integrins can promote axon regeneration in the adult central nervous system (CNS). There are two obstacles that prevent integrin-mediated regeneration in the CNS: 1) integrins are not localised in the axon of most adult CNS neurons and 2) integrins become inactivated by molecules in the scar tissue after injury.[27]

Vertebrate integrins edit

The following are 16 of the ~24 integrins found in vertebrates:

Name Synonyms Distribution Ligands
α1β1 VLA-1 Many Collagens, laminins[28]
α2β1 VLA-2 Many Collagens, laminins[28]
α3β1 VLA-3 Many Laminin-5
α4β1 VLA-4[28] Hematopoietic cells Fibronectin, VCAM-1[28]
α4β7 LPAM-1 T cells MAD-CAM1[29][30]
α5β1 VLA-5; fibronectin receptor widespread fibronectin[28] and proteinases
α6β1 VLA-6; laminin receptor widespread laminins
α7β1 muscle, glioma laminins
αLβ2 LFA-1[28] T-lymphocytes ICAM-1, ICAM-2[28]
αMβ2 Mac-1, CR3[28] Neutrophils and monocytes Serum proteins, ICAM-1[28]
αIIbβ3 Fibrinogen receptor; gpIIbIIIa[31] Platelets[28] fibrinogen, fibronectin[28]
αVβ1 neurological tumors vitronectin, osteopontin,[32] fibrinogen
αVβ3 vitronectin receptor[33] activated endothelial cells, melanoma, glioblastoma vitronectin,[33] fibronectin, fibrinogen, osteopontin,[32] Cyr61, thyroxine,[34] TETRAC
αVβ5 widespread, esp. fibroblasts, epithelial cells vitronectin, osteopontin,[32] and adenovirus
αVβ6 proliferating epithelia, esp. lung and mammary gland fibronectin; TGFβ1+3
αVβ8 neural tissue; peripheral nerve fibronectin; TGFβ1+3
α6β4 Epithelial cells[28] Laminin[28]

Beta-1 integrins interact with many alpha integrin chains. Gene knockouts of integrins in mice are not always lethal, which suggests that during embryonal development, one integrin may substitute its function for another in order to allow survival. Some integrins are on the cell surface in an inactive state, and can be rapidly primed, or put into a state capable of binding their ligands, by cytokines. Integrins can assume several different well-defined shapes or "conformational states". Once primed, the conformational state changes to stimulate ligand binding, which then activates the receptors — also by inducing a shape change — to trigger outside-in signal transduction.

See also edit

References edit

  1. ^ a b Xiong JP, Stehle T, Diefenbach B, Zhang R, Dunker R, Scott DL, Joachimiak A, Goodman SL, Arnaout MA (October 2001). "Crystal structure of the extracellular segment of integrin alpha Vbeta3". Science. 294 (5541): 339–45. Bibcode:2001Sci...294..339X. doi:10.1126/science.1064535. PMC 2885948. PMID 11546839.
  2. ^ Sauer FG, Fütterer K, Pinkner JS, Dodson KW, Hultgren SJ, Waksman G (August 1999). "Structural basis of chaperone function and pilus biogenesis". Science. 285 (5430): 1058–61. doi:10.1126/science.285.5430.1058. PMID 10446050.
  3. ^ a b Hynes RO (September 2002). "Integrins: bidirectional, allosteric signaling machines". Cell. 110 (6): 673–87. doi:10.1016/s0092-8674(02)00971-6. PMID 12297042. S2CID 30326350.
  4. ^ Giancotti FG, Ruoslahti E (August 1999). "Integrin signaling". Science. 285 (5430): 1028–32. doi:10.1126/science.285.5430.1028. PMID 10446041.
  5. ^ Bruce A, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2002). "Integrins". Molecular Biology of the Cell (4th ed.). New York: Garland Science.
  6. ^ Humphries MJ (2000). "Integrin structure". Biochemical Society Transactions. 28 (4): 311–39. doi:10.1042/0300-5127:0280311. PMID 10961914.
  7. ^ Nermut MV, Green NM, Eason P, Yamada SS, Yamada KM (December 1988). "Electron microscopy and structural model of human fibronectin receptor". The EMBO Journal. 7 (13): 4093–9. doi:10.1002/j.1460-2075.1988.tb03303.x. PMC 455118. PMID 2977331.
  8. ^ Hynes RO (September 2002). "Integrins: bidirectional, allosteric signaling machines". Cell. 110 (6): 673–87. doi:10.1016/S0092-8674(02)00971-6. PMID 12297042. S2CID 30326350.
  9. ^ Smith JW (June 2003). "Cilengitide Merck". Current Opinion in Investigational Drugs. 4 (6): 741–5. PMID 12901235.
  10. ^ Calderwood DA (June 2004). "Talin controls integrin activation". Biochemical Society Transactions. 32 (Pt3): 434–7. doi:10.1042/BST0320434. PMID 15157154.
  11. ^ Calderwood DA, Zent R, Grant R, Rees DJ, Hynes RO, Ginsberg MH (October 1999). "The Talin head domain binds to integrin beta subunit cytoplasmic tails and regulates integrin activation". The Journal of Biological Chemistry. 274 (40): 28071–4. doi:10.1074/jbc.274.40.28071. PMID 10497155.
  12. ^ Shattil SJ, Kim C, Ginsberg MH (April 2010). "The final steps of integrin activation: the end game". Nature Reviews. Molecular Cell Biology. 11 (4): 288–300. doi:10.1038/nrm2871. PMC 3929966. PMID 20308986.
  13. ^ Goldmann WH, Bremer A, Häner M, Aebi U, Isenberg G (1994). "Native talin is a dumbbell-shaped homodimer when it interacts with actin". Journal of Structural Biology. 112 (1): 3–10. doi:10.1006/jsbi.1994.1002. PMID 8031639.
  14. ^ Harburger DS, Bouaouina M, Calderwood DA (April 2009). "Kindlin-1 and -2 directly bind the C-terminal region of beta integrin cytoplasmic tails and exert integrin-specific activation effects". The Journal of Biological Chemistry. 284 (17): 11485–97. doi:10.1074/jbc.M809233200. PMC 2670154. PMID 19240021.
  15. ^ Yamada KM, Miyamoto S (October 1995). "Integrin transmembrane signaling and cytoskeletal control". Current Opinion in Cell Biology. 7 (5): 681–9. doi:10.1016/0955-0674(95)80110-3. PMID 8573343.
  16. ^ Banerjee, S; Nara, R; Chakraborty, S; Chowdhury, D; Haldar, S (2022). "Integrin Regulated Autoimmune Disorders: Understanding the Role of Mechanical Force in Autoimmunity". Frontiers in Cell and Developmental Biology. 10: 852878. doi:10.3389/fcell.2022.852878. PMC 8971850. PMID 35372360.
  17. ^ Wilhelmsen K, Litjens SH, Sonnenberg A (April 2006). "Multiple functions of the integrin alpha6beta4 in epidermal homeostasis and tumorigenesis". Molecular and Cellular Biology. 26 (8): 2877–86. doi:10.1128/MCB.26.8.2877-2886.2006. PMC 1446957. PMID 16581764.
  18. ^ Olberding JE, Thouless MD, Arruda EM, Garikipati K (August 2010). Buehler MJ (ed.). "The non-equilibrium thermodynamics and kinetics of focal adhesion dynamics". PLOS ONE. 5 (8): e12043. Bibcode:2010PLoSO...512043O. doi:10.1371/journal.pone.0012043. PMC 2923603. PMID 20805876.
  19. ^ Patla I, Volberg T, Elad N, Hirschfeld-Warneken V, Grashoff C, Fässler R, Spatz JP, Geiger B, Medalia O (September 2010). "Dissecting the molecular architecture of integrin adhesion sites by cryo-electron tomography". Nature Cell Biology. 12 (9): 909–15. doi:10.1038/ncb2095. PMID 20694000. S2CID 20775305.
  20. ^ Gullingsrud J, Sotomayor M. "Mechanosensitive channels". Theoretical and Computational Biophysics Group, Beckman Institute for Advanced Science and Technology: University of Illinois at Urbana-Champaign. from the original on 2010-12-02.
  21. ^ Paul NR, Jacquemet G, Caswell PT (November 2015). "Endocytic Trafficking of Integrins in Cell Migration". Current Biology. 25 (22): R1092-105. doi:10.1016/j.cub.2015.09.049. PMID 26583903.
  22. ^ Moreno-Layseca P, Icha J, Hamidi H, Ivaska J (February 2019). "Integrin trafficking in cells and tissues". Nature Cell Biology. 21 (2): 122–132. doi:10.1038/s41556-018-0223-z. PMC 6597357. PMID 30602723.
  23. ^ Goel HL, Breen M, Zhang J, Das I, Aznavoorian-Cheshire S, Greenberg NM, Elgavish A, Languino LR (August 2005). "beta1A integrin expression is required for type 1 insulin-like growth factor receptor mitogenic and transforming activities and localization to focal contacts". Cancer Research. 65 (15): 6692–700. doi:10.1158/0008-5472.CAN-04-4315. PMID 16061650.
  24. ^ Kim SH, Turnbull J, Guimond S (May 2011). "Extracellular matrix and cell signalling: the dynamic cooperation of integrin, proteoglycan and growth factor receptor". The Journal of Endocrinology. 209 (2): 139–51. doi:10.1530/JOE-10-0377. PMID 21307119.
  25. ^ a b c Bostwick DG, Cheng L (2020-01-01). "9 - Neoplasms of the Prostate". In Cheng L, MacLennan GT, Bostwick DG (eds.). Urologic Surgical Pathology (Fourth ed.). Philadelphia: Content Repository Only!. pp. 415–525.e42. ISBN 978-0-323-54941-7.
  26. ^ Carbonell WS, DeLay M, Jahangiri A, Park CC, Aghi MK (May 2013). "β1 integrin targeting potentiates antiangiogenic therapy and inhibits the growth of bevacizumab-resistant glioblastoma". Cancer Research. 73 (10): 3145–54. doi:10.1158/0008-5472.CAN-13-0011. PMC 4040366. PMID 23644530.
  27. ^ a b c Nieuwenhuis B, Haenzi B, Andrews MR, Verhaagen J, Fawcett JW (February 2018). "Integrins promote axonal regeneration after injury of the nervous system". Biological Reviews of the Cambridge Philosophical Society. 93 (3): 1339–1362. doi:10.1111/brv.12398. PMC 6055631. PMID 29446228.
  28. ^ a b c d e f g h i j k l m Krieger M, Scott MP, Matsudaira PT, Lodish HF, Darnell JE, Zipursky L, Kaiser C, Berk A (2004). Molecular cell biology (fifth ed.). New York: W.H. Freeman and CO. ISBN 978-0-7167-4366-8.
  29. ^ Wang, Caihong; McDonough, Jacquelyn S.; McDonald, Keely G.; Huang, Conway; Newberry, Rodney D. (2008-09-15). "Alpha4beta7/MAdCAM-1 interactions play an essential role in transitioning cryptopatches into isolated lymphoid follicles and a nonessential role in cryptopatch formation". Journal of Immunology. 181 (6): 4052–4061. doi:10.4049/jimmunol.181.6.4052. ISSN 1550-6606. PMC 2778276. PMID 18768861.
  30. ^ Wagner, N.; Löhler, J.; Kunkel, E. J.; Ley, K.; Leung, E.; Krissansen, G.; Rajewsky, K.; Müller, W. (1996-07-25). "Critical role for beta7 integrins in formation of the gut-associated lymphoid tissue". Nature. 382 (6589): 366–370. doi:10.1038/382366a0. ISSN 0028-0836. PMID 8684468.
  31. ^ Elangbam CS, Qualls CW, Dahlgren RR (January 1997). "Cell adhesion molecules--update". Veterinary Pathology. 34 (1): 61–73. doi:10.1177/030098589703400113. PMID 9150551.
  32. ^ a b c Kazanecki, CC; Uzwiak, DJ; Denhxxardt, DT (1 November 2007). "Control of osteopontin signaling and function by post-translational phosphorylation and protein folding". Journal of Cellular Biochemistry. 102 (4): 912–24. doi:10.1002/jcb.21558. PMID 17910028. S2CID 24240459.
  33. ^ a b Hermann P, Armant M, Brown E, Rubio M, Ishihara H, Ulrich D, Caspary RG, Lindberg FP, Armitage R, Maliszewski C, Delespesse G, Sarfati M (February 1999). "The vitronectin receptor and its associated CD47 molecule mediates proinflammatory cytokine synthesis in human monocytes by interaction with soluble CD23". The Journal of Cell Biology. 144 (4): 767–75. doi:10.1083/jcb.144.4.767. PMC 2132927. PMID 10037797.
  34. ^ Bergh JJ, Lin HY, Lansing L, Mohamed SN, Davis FB, Mousa S, Davis PJ (July 2005). "Integrin alphaVbeta3 contains a cell surface receptor site for thyroid hormone that is linked to activation of mitogen-activated protein kinase and induction of angiogenesis". Endocrinology. 146 (7): 2864–71. doi:10.1210/en.2005-0102. PMID 15802494.

External links edit

  Media related to Integrins at Wikimedia Commons

integrin, transmembrane, receptors, that, help, cell, cell, cell, extracellular, matrix, adhesion, upon, ligand, binding, integrins, activate, signal, transduction, pathways, that, mediate, cellular, signals, such, regulation, cell, cycle, organization, intrac. Integrins are transmembrane receptors that help cell cell and cell extracellular matrix ECM adhesion 3 Upon ligand binding integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle organization of the intracellular cytoskeleton and movement of new receptors to the cell membrane 4 The presence of integrins allows rapid and flexible responses to events at the cell surface e g signal platelets to initiate an interaction with coagulation factors Integrin alphaVbeta3 extracellular domainsStructure of the extracellular segment of integrin alpha Vbeta3 1 IdentifiersSymbolIntegrin alphaVbeta3PfamPF08441Pfam clanCL0159InterProIPR013649SCOP21jv2 SCOPe SUPFAMOPM superfamily176OPM protein2kncMembranome13Available protein structures Pfam structures ECOD PDBRCSB PDB PDBe PDBjPDBsumstructure summary Integrin alpha cytoplasmic regionStructure of chaperone protein PAPD 2 IdentifiersSymbolIntegrin alphaPfamPF00357InterProIPR000413PROSITEPDOC00215SCOP21dpk SCOPe SUPFAMAvailable protein structures Pfam structures ECOD PDBRCSB PDB PDBe PDBjPDBsumstructure summary Integrin beta chain vWA IdentifiersSymbolIntegrin betaPfamPF00362InterProIPR002369SMARTSM00187PROSITEPDOC00216SCOP21jv2 SCOPe SUPFAMAvailable protein structures Pfam structures ECOD PDBRCSB PDB PDBe PDBjPDBsumstructure summaryPDB1jv2 1kup 1kuz 1l3y 1l5g 1m1x 1m8o 1s4x 1txv 1ty3 1ty5 1ty6 1ty7 1tye 1u8c Integrin beta 7 cytoplasmic domain complex with filamincrystal structure of the filamin a repeat 21 complexed with the integrin beta7 cytoplasmic tail peptideIdentifiersSymbolIntegrin b cytPfamPF08725InterProIPR014836SCOP21m8O SCOPe SUPFAMAvailable protein structures Pfam structures ECOD PDBRCSB PDB PDBe PDBjPDBsumstructure summary Several types of integrins exist and one cell generally has multiple different types on its surface Integrins are found in all animals while integrin like receptors are found in plant cells 3 Integrins work alongside other proteins such as cadherins the immunoglobulin superfamily cell adhesion molecules selectins and syndecans to mediate cell cell and cell matrix interaction Ligands for integrins include fibronectin vitronectin collagen and laminin Contents 1 Structure 1 1 Structure 1 2 Activation 2 Function 2 1 Attachment of cell to the ECM 2 2 Signal transduction 3 Integrins and nerve repair 4 Vertebrate integrins 5 See also 6 References 7 External linksStructure editIntegrins are obligate heterodimers composed of a and b subunits Several genes code for multiple isoforms of these subunits which gives rise to an array of unique integrins with varied activity In mammals integrins are assembled from eighteen a and eight b subunits 5 in Drosophila five a and two b subunits and in Caenorhabditis nematodes two a subunits and one b subunit 6 The a and b subunits are both class I transmembrane proteins so each penetrates the plasma membrane once and can possess several cytoplasmic domains 7 alpha mammal gene protein synonyms ITGA1 CD49a VLA1 ITGA2 CD49b VLA2 ITGA3 CD49c VLA3 ITGA4 CD49d VLA4 ITGA5 CD49e VLA5 ITGA6 CD49f VLA6 ITGA7 ITGA7 FLJ25220 ITGA8 ITGA8 ITGA9 ITGA9 RLC ITGA10 ITGA10 PRO827 ITGA11 ITGA11 HsT18964 ITGAD CD11D FLJ39841 ITGAE CD103 HUMINAE ITGAL CD11a LFA1A ITGAM CD11b MAC 1 ITGAV CD51 VNRA MSK8 ITGA2B CD41 GPIIb ITGAX CD11c beta mammal gene protein synonyms ITGB1 CD29 FNRB MSK12 MDF2 ITGB2 CD18 LFA 1 MAC 1 MFI7 ITGB3 CD61 GP3A GPIIIa ITGB4 CD104 ITGB5 ITGB5 FLJ26658 ITGB6 ITGB6 ITGB7 ITGB7 ITGB8 ITGB8 Variants of some subunits are formed by differential RNA splicing for example four variants of the beta 1 subunit exist Through different combinations of the a and b subunits 24 unique mammalian integrins are generated excluding splice and glycosylation variants 8 Integrin subunits span the cell membrane and have short cytoplasmic domains of 40 70 amino acids The exception is the beta 4 subunit which has a cytoplasmic domain of 1 088 amino acids one of the largest of any membrane protein Outside the cell membrane the a and b chains lie close together along a length of about 23 nm the final 5 nm N termini of each chain forms a ligand binding region for the ECM They have been compared to lobster claws although they don t actually pinch their ligand they chemically interact with it at the insides of the tips of their pinchers The molecular mass of the integrin subunits can vary from 90 kDa to 160 kDa Beta subunits have four cysteine rich repeated sequences Both a and b subunits bind several divalent cations The role of divalent cations in the a subunit is unknown but may stabilize the folds of the protein The cations in the b subunits are more interesting they are directly involved in coordinating at least some of the ligands that integrins bind Integrins can be categorized in multiple ways For example some a chains have an additional structural element or domain inserted toward the N terminal the alpha A domain so called because it has a similar structure to the A domains found in the protein von Willebrand factor it is also termed the a I domain Integrins carrying this domain either bind to collagens e g integrins a1 b1 and a2 b1 or act as cell cell adhesion molecules integrins of the b2 family This a I domain is the binding site for ligands of such integrins Those integrins that don t carry this inserted domain also have an A domain in their ligand binding site but this A domain is found on the b subunit In both cases the A domains carry up to three divalent cation binding sites One is permanently occupied in physiological concentrations of divalent cations and carries either a calcium or magnesium ion the principal divalent cations in blood at median concentrations of 1 4 mM calcium and 0 8 mM magnesium The other two sites become occupied by cations when ligands bind at least for those ligands involving an acidic amino acid in their interaction sites An acidic amino acid features in the integrin interaction site of many ECM proteins for example as part of the amino acid sequence Arginine Glycine Aspartic acid RGD in the one letter amino acid code Structure edit Despite many years of effort discovering the high resolution structure of integrins proved to be challenging as membrane proteins are classically difficult to purify and as integrins are large complex and highly glycosylated with many sugar trees attached to them Low resolution images of detergent extracts of intact integrin GPIIbIIIa obtained using electron microscopy and even data from indirect techniques that investigate the solution properties of integrins using ultracentrifugation and light scattering were combined with fragmentary high resolution crystallographic or NMR data from single or paired domains of single integrin chains and molecular models postulated for the rest of the chains The X ray crystal structure obtained for the complete extracellular region of one integrin avb3 1 shows the molecule to be folded into an inverted V shape that potentially brings the ligand binding sites close to the cell membrane Perhaps more importantly the crystal structure was also obtained for the same integrin bound to a small ligand containing the RGD sequence the drug cilengitide 9 As detailed above this finally revealed why divalent cations in the A domains are critical for RGD ligand binding to integrins The interaction of such sequences with integrins is believed to be a primary switch by which ECM exerts its effects on cell behaviour The structure poses many questions especially regarding ligand binding and signal transduction The ligand binding site is directed towards the C terminal of the integrin the region where the molecule emerges from the cell membrane If it emerges orthogonally from the membrane the ligand binding site would apparently be obstructed especially as integrin ligands are typically massive and well cross linked components of the ECM In fact little is known about the angle that membrane proteins subtend to the plane of the membrane this is a problem difficult to address with available technologies The default assumption is that they emerge rather like little lollipops but there is little evidence for this The integrin structure has drawn attention to this problem which may have general implications for how membrane proteins work It appears that the integrin transmembrane helices are tilted see Activation below which hints that the extracellular chains may also not be orthogonal with respect to the membrane surface Although the crystal structure changed surprisingly little after binding to cilengitide the current hypothesis is that integrin function involves changes in shape to move the ligand binding site into a more accessible position away from the cell surface and this shape change also triggers intracellular signaling There is a wide body of cell biological and biochemical literature that supports this view Perhaps the most convincing evidence involves the use of antibodies that only recognize integrins when they have bound to their ligands or are activated As the footprint that an antibody makes on its binding target is roughly a circle about 3 nm in diameter the resolution of this technique is low Nevertheless these so called LIBS Ligand Induced Binding Sites antibodies unequivocally show that dramatic changes in integrin shape routinely occur However how the changes detected with antibodies look on the structure is still unknown Activation edit When released into the cell membrane newly synthesized integrin dimers are speculated to be found in the same bent conformation revealed by the structural studies described above One school of thought claims that this bent form prevents them from interacting with their ligands although bent forms can predominate in high resolution EM structures of integrin bound to an ECM ligand Therefore at least in biochemical experiments integrin dimers must apparently not be unbent in order to prime them and allow their binding to the ECM In cells the priming is accomplished by a protein talin which binds to the b tail of the integrin dimer and changes its conformation 10 11 The a and b integrin chains are both class I transmembrane proteins they pass the plasma membrane as single transmembrane alpha helices Unfortunately the helices are too long and recent studies suggest that for integrin gpIIbIIIa they are tilted with respect both to one another and to the plane of the membrane Talin binding alters the angle of tilt of the b3 chain transmembrane helix in model systems and this may reflect a stage in the process of inside out signalling which primes integrins 12 Moreover talin proteins are able to dimerize 13 and thus are thought to intervene in the clustering of integrin dimers which leads to the formation of a focal adhesion Recently the Kindlin 1 and Kindlin 2 proteins have also been found to interact with integrin and activate it 14 Function editIntegrins have two main functions attachment of the cells to the ECM and signal transduction from the ECM to the cells 15 They are also involved in a wide range of other biological activities including extravasation cell to cell adhesion cell migration and as receptors for certain viruses such as adenovirus echovirus hantavirus foot and mouth disease polio virus and other viruses Recently the importance of integrins in the progress of autoimmune disorders is also gaining attention of the scientists These mechanoreceptors seem to regulate autoimmunity by dictating various intracellular pathways to control immune cell adhesion to endothelial cell layers followed by their trans migration This process might or might not be dependent on the sheer force faced by the extracellular parts of different integrins 16 A prominent function of the integrins is seen in the molecule GpIIb IIIa an integrin on the surface of blood platelets thrombocytes responsible for attachment to fibrin within a developing blood clot This molecule dramatically increases its binding affinity for fibrin fibrinogen through association of platelets with exposed collagens in the wound site Upon association of platelets with collagen GPIIb IIIa changes shape allowing it to bind to fibrin and other blood components to form the clot matrix and stop blood loss Attachment of cell to the ECM edit Integrins couple the cell extracellular matrix ECM outside a cell to the cytoskeleton in particular the microfilaments inside the cell Which ligand in the ECM the integrin can bind to is defined by which a and b subunits the integrin is made of Among the ligands of integrins are fibronectin vitronectin collagen and laminin The connection between the cell and the ECM may help the cell to endure pulling forces without being ripped out of the ECM The ability of a cell to create this kind of bond is also of vital importance in ontogeny Cell attachment to the ECM is a basic requirement to build a multicellular organism Integrins are not simply hooks but give the cell critical signals about the nature of its surroundings Together with signals arising from receptors for soluble growth factors like VEGF EGF and many others they enforce a cellular decision on what biological action to take be it attachment movement death or differentiation Thus integrins lie at the heart of many cellular biological processes The attachment of the cell takes place through formation of cell adhesion complexes which consist of integrins and many cytoplasmic proteins such as talin vinculin paxillin and alpha actinin These act by regulating kinases such as FAK focal adhesion kinase and Src kinase family members to phosphorylate substrates such as p130CAS thereby recruiting signaling adaptors such as CRK These adhesion complexes attach to the actin cytoskeleton The integrins thus serve to link two networks across the plasma membrane the extracellular ECM and the intracellular actin filamentous system Integrin a6b4 is an exception it links to the keratin intermediate filament system in epithelial cells 17 Focal adhesions are large molecular complexes which are generated following interaction of integrins with ECM then their clustering The clusters likely provide sufficient intracellular binding sites to permit the formation of stable signaling complexes on the cytoplasmic side of the cell membrane So the focal adhesions contain integrin ligand integrin molecule and associate plaque proteins Binding is propelled by changes in free energy 18 As previously stated these complexes connect the extracellular matrix to actin bundles Cryo electron tomography reveals that the adhesion contains particles on the cell membrane with diameter of 25 5 nm and spaced at approximately 45 nm 19 Treatment with Rho kinase inhibitor Y 27632 reduces the size of the particle and it is extremely mechanosensitive 20 One important function of integrins on cells in tissue culture is their role in cell migration Cells adhere to a substrate through their integrins During movement the cell makes new attachments to the substrate at its front and concurrently releases those at its rear When released from the substrate integrin molecules are taken back into the cell by endocytosis they are transported through the cell to its front by the endocytic cycle where they are added back to the surface In this way they are cycled for reuse enabling the cell to make fresh attachments at its leading front 21 The cycle of integrin endocytosis and recycling back to the cell surface is important also for not migrating cells and during animal development 22 Signal transduction edit Integrins play an important role in cell signaling by modulating the cell signaling pathways of transmembrane protein kinases such as receptor tyrosine kinases RTK While the interaction between integrin and receptor tyrosine kinases originally was thought of as uni directional and supportive recent studies indicate that integrins have additional multi faceted roles in cell signaling Integrins can regulate the receptor tyrosine kinase signaling by recruiting specific adaptors to the plasma membrane For example b1c integrin recruits Gab1 Shp2 and presents Shp2 to IGF1R resulting in dephosphorylation of the receptor 23 In a reverse direction when a receptor tyrosine kinase is activated integrins co localise at focal adhesion with the receptor tyrosine kinases and their associated signaling molecules The repertoire of integrins expressed on a particular cell can specify the signaling pathway due to the differential binding affinity of ECM ligands for the integrins The tissue stiffness and matrix composition can initiate specific signaling pathways regulating cell behavior Clustering and activation of the integrins actin complexes strengthen the focal adhesion interaction and initiate the framework for cell signaling through assembly of adhesomes 24 Depending on the integrin s regulatory impact on specific receptor tyrosine kinases the cell can experience cell growth 25 cell division 25 cell survival 25 cellular differentiation apoptosis programmed cell death Knowledge of the relationship between integrins and receptor tyrosine kinase has laid a foundation for new approaches to cancer therapy Specifically targeting integrins associated with RTKs is an emerging approach for inhibiting angiogenesis 26 nbsp Integrins are localised at the growth cone of regenerating neurons 27 Integrins and nerve repair editIntegrins have an important function in neuroregeneration after injury of the peripheral nervous system PNS 27 Integrins are present at the growth cone of damaged PNS neurons and attach to ligands in the ECM to promote axon regeneration It is unclear whether integrins can promote axon regeneration in the adult central nervous system CNS There are two obstacles that prevent integrin mediated regeneration in the CNS 1 integrins are not localised in the axon of most adult CNS neurons and 2 integrins become inactivated by molecules in the scar tissue after injury 27 Vertebrate integrins editThe following are 16 of the 24 integrins found in vertebrates Name Synonyms Distribution Ligands a1b1 VLA 1 Many Collagens laminins 28 a2b1 VLA 2 Many Collagens laminins 28 a3b1 VLA 3 Many Laminin 5 a4b1 VLA 4 28 Hematopoietic cells Fibronectin VCAM 1 28 a4b7 LPAM 1 T cells MAD CAM1 29 30 a5b1 VLA 5 fibronectin receptor widespread fibronectin 28 and proteinases a6b1 VLA 6 laminin receptor widespread laminins a7b1 muscle glioma laminins aLb2 LFA 1 28 T lymphocytes ICAM 1 ICAM 2 28 aMb2 Mac 1 CR3 28 Neutrophils and monocytes Serum proteins ICAM 1 28 aIIbb3 Fibrinogen receptor gpIIbIIIa 31 Platelets 28 fibrinogen fibronectin 28 aVb1 neurological tumors vitronectin osteopontin 32 fibrinogen aVb3 vitronectin receptor 33 activated endothelial cells melanoma glioblastoma vitronectin 33 fibronectin fibrinogen osteopontin 32 Cyr61 thyroxine 34 TETRAC aVb5 widespread esp fibroblasts epithelial cells vitronectin osteopontin 32 and adenovirus aVb6 proliferating epithelia esp lung and mammary gland fibronectin TGFb1 3 aVb8 neural tissue peripheral nerve fibronectin TGFb1 3 a6b4 Epithelial cells 28 Laminin 28 Beta 1 integrins interact with many alpha integrin chains Gene knockouts of integrins in mice are not always lethal which suggests that during embryonal development one integrin may substitute its function for another in order to allow survival Some integrins are on the cell surface in an inactive state and can be rapidly primed or put into a state capable of binding their ligands by cytokines Integrins can assume several different well defined shapes or conformational states Once primed the conformational state changes to stimulate ligand binding which then activates the receptors also by inducing a shape change to trigger outside in signal transduction See also editD dimer Disintegrin Exopolymer Extracellular polymeric substance EPS or XPS References edit a b Xiong JP Stehle T Diefenbach B Zhang R Dunker R Scott DL Joachimiak A Goodman SL Arnaout MA October 2001 Crystal structure of the extracellular segment of integrin alpha Vbeta3 Science 294 5541 339 45 Bibcode 2001Sci 294 339X doi 10 1126 science 1064535 PMC 2885948 PMID 11546839 Sauer FG Futterer K Pinkner JS Dodson KW Hultgren SJ Waksman G August 1999 Structural basis of chaperone function and pilus biogenesis Science 285 5430 1058 61 doi 10 1126 science 285 5430 1058 PMID 10446050 a b Hynes RO September 2002 Integrins bidirectional allosteric signaling machines Cell 110 6 673 87 doi 10 1016 s0092 8674 02 00971 6 PMID 12297042 S2CID 30326350 Giancotti FG Ruoslahti E August 1999 Integrin signaling Science 285 5430 1028 32 doi 10 1126 science 285 5430 1028 PMID 10446041 Bruce A Johnson A Lewis J Raff M Roberts K Walter P 2002 Integrins Molecular Biology of the Cell 4th ed New York Garland Science Humphries MJ 2000 Integrin structure Biochemical Society Transactions 28 4 311 39 doi 10 1042 0300 5127 0280311 PMID 10961914 Nermut MV Green NM Eason P Yamada SS Yamada KM December 1988 Electron microscopy and structural model of human fibronectin receptor The EMBO Journal 7 13 4093 9 doi 10 1002 j 1460 2075 1988 tb03303 x PMC 455118 PMID 2977331 Hynes RO September 2002 Integrins bidirectional allosteric signaling machines Cell 110 6 673 87 doi 10 1016 S0092 8674 02 00971 6 PMID 12297042 S2CID 30326350 Smith JW June 2003 Cilengitide Merck Current Opinion in Investigational Drugs 4 6 741 5 PMID 12901235 Calderwood DA June 2004 Talin controls integrin activation Biochemical Society Transactions 32 Pt3 434 7 doi 10 1042 BST0320434 PMID 15157154 Calderwood DA Zent R Grant R Rees DJ Hynes RO Ginsberg MH October 1999 The Talin head domain binds to integrin beta subunit cytoplasmic tails and regulates integrin activation The Journal of Biological Chemistry 274 40 28071 4 doi 10 1074 jbc 274 40 28071 PMID 10497155 Shattil SJ Kim C Ginsberg MH April 2010 The final steps of integrin activation the end game Nature Reviews Molecular Cell Biology 11 4 288 300 doi 10 1038 nrm2871 PMC 3929966 PMID 20308986 Goldmann WH Bremer A Haner M Aebi U Isenberg G 1994 Native talin is a dumbbell shaped homodimer when it interacts with actin Journal of Structural Biology 112 1 3 10 doi 10 1006 jsbi 1994 1002 PMID 8031639 Harburger DS Bouaouina M Calderwood DA April 2009 Kindlin 1 and 2 directly bind the C terminal region of beta integrin cytoplasmic tails and exert integrin specific activation effects The Journal of Biological Chemistry 284 17 11485 97 doi 10 1074 jbc M809233200 PMC 2670154 PMID 19240021 Yamada KM Miyamoto S October 1995 Integrin transmembrane signaling and cytoskeletal control Current Opinion in Cell Biology 7 5 681 9 doi 10 1016 0955 0674 95 80110 3 PMID 8573343 Banerjee S Nara R Chakraborty S Chowdhury D Haldar S 2022 Integrin Regulated Autoimmune Disorders Understanding the Role of Mechanical Force in Autoimmunity Frontiers in Cell and Developmental Biology 10 852878 doi 10 3389 fcell 2022 852878 PMC 8971850 PMID 35372360 Wilhelmsen K Litjens SH Sonnenberg A April 2006 Multiple functions of the integrin alpha6beta4 in epidermal homeostasis and tumorigenesis Molecular and Cellular Biology 26 8 2877 86 doi 10 1128 MCB 26 8 2877 2886 2006 PMC 1446957 PMID 16581764 Olberding JE Thouless MD Arruda EM Garikipati K August 2010 Buehler MJ ed The non equilibrium thermodynamics and kinetics of focal adhesion dynamics PLOS ONE 5 8 e12043 Bibcode 2010PLoSO 512043O doi 10 1371 journal pone 0012043 PMC 2923603 PMID 20805876 Patla I Volberg T Elad N Hirschfeld Warneken V Grashoff C Fassler R Spatz JP Geiger B Medalia O September 2010 Dissecting the molecular architecture of integrin adhesion sites by cryo electron tomography Nature Cell Biology 12 9 909 15 doi 10 1038 ncb2095 PMID 20694000 S2CID 20775305 Gullingsrud J Sotomayor M Mechanosensitive channels Theoretical and Computational Biophysics Group Beckman Institute for Advanced Science and Technology University of Illinois at Urbana Champaign Archived from the original on 2010 12 02 Paul NR Jacquemet G Caswell PT November 2015 Endocytic Trafficking of Integrins in Cell Migration Current Biology 25 22 R1092 105 doi 10 1016 j cub 2015 09 049 PMID 26583903 Moreno Layseca P Icha J Hamidi H Ivaska J February 2019 Integrin trafficking in cells and tissues Nature Cell Biology 21 2 122 132 doi 10 1038 s41556 018 0223 z PMC 6597357 PMID 30602723 Goel HL Breen M Zhang J Das I Aznavoorian Cheshire S Greenberg NM Elgavish A Languino LR August 2005 beta1A integrin expression is required for type 1 insulin like growth factor receptor mitogenic and transforming activities and localization to focal contacts Cancer Research 65 15 6692 700 doi 10 1158 0008 5472 CAN 04 4315 PMID 16061650 Kim SH Turnbull J Guimond S May 2011 Extracellular matrix and cell signalling the dynamic cooperation of integrin proteoglycan and growth factor receptor The Journal of Endocrinology 209 2 139 51 doi 10 1530 JOE 10 0377 PMID 21307119 a b c Bostwick DG Cheng L 2020 01 01 9 Neoplasms of the Prostate In Cheng L MacLennan GT Bostwick DG eds Urologic Surgical Pathology Fourth ed Philadelphia Content Repository Only pp 415 525 e42 ISBN 978 0 323 54941 7 Carbonell WS DeLay M Jahangiri A Park CC Aghi MK May 2013 b1 integrin targeting potentiates antiangiogenic therapy and inhibits the growth of bevacizumab resistant glioblastoma Cancer Research 73 10 3145 54 doi 10 1158 0008 5472 CAN 13 0011 PMC 4040366 PMID 23644530 a b c Nieuwenhuis B Haenzi B Andrews MR Verhaagen J Fawcett JW February 2018 Integrins promote axonal regeneration after injury of the nervous system Biological Reviews of the Cambridge Philosophical Society 93 3 1339 1362 doi 10 1111 brv 12398 PMC 6055631 PMID 29446228 a b c d e f g h i j k l m Krieger M Scott MP Matsudaira PT Lodish HF Darnell JE Zipursky L Kaiser C Berk A 2004 Molecular cell biology fifth ed New York W H Freeman and CO ISBN 978 0 7167 4366 8 Wang Caihong McDonough Jacquelyn S McDonald Keely G Huang Conway Newberry Rodney D 2008 09 15 Alpha4beta7 MAdCAM 1 interactions play an essential role in transitioning cryptopatches into isolated lymphoid follicles and a nonessential role in cryptopatch formation Journal of Immunology 181 6 4052 4061 doi 10 4049 jimmunol 181 6 4052 ISSN 1550 6606 PMC 2778276 PMID 18768861 Wagner N Lohler J Kunkel E J Ley K Leung E Krissansen G Rajewsky K Muller W 1996 07 25 Critical role for beta7 integrins in formation of the gut associated lymphoid tissue Nature 382 6589 366 370 doi 10 1038 382366a0 ISSN 0028 0836 PMID 8684468 Elangbam CS Qualls CW Dahlgren RR January 1997 Cell adhesion molecules update Veterinary Pathology 34 1 61 73 doi 10 1177 030098589703400113 PMID 9150551 a b c Kazanecki CC Uzwiak DJ Denhxxardt DT 1 November 2007 Control of osteopontin signaling and function by post translational phosphorylation and protein folding Journal of Cellular Biochemistry 102 4 912 24 doi 10 1002 jcb 21558 PMID 17910028 S2CID 24240459 a b Hermann P Armant M Brown E Rubio M Ishihara H Ulrich D Caspary RG Lindberg FP Armitage R Maliszewski C Delespesse G Sarfati M February 1999 The vitronectin receptor and its associated CD47 molecule mediates proinflammatory cytokine synthesis in human monocytes by interaction with soluble CD23 The Journal of Cell Biology 144 4 767 75 doi 10 1083 jcb 144 4 767 PMC 2132927 PMID 10037797 Bergh JJ Lin HY Lansing L Mohamed SN Davis FB Mousa S Davis PJ July 2005 Integrin alphaVbeta3 contains a cell surface receptor site for thyroid hormone that is linked to activation of mitogen activated protein kinase and induction of angiogenesis Endocrinology 146 7 2864 71 doi 10 1210 en 2005 0102 PMID 15802494 External links edit nbsp Media related to Integrins at Wikimedia Commons Talin substrate for calpain PMAP The Proteolysis Map animation Integrins at the U S National Library of Medicine Medical Subject Headings MeSH Retrieved from https en wikipedia org w index php title Integrin amp oldid 1223462570 Signal transduction, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.