This highly conserved glycoprotein is a precursor for 4 cleavage products: saposins A, B, C, and D. Saposin is an acronym for Sphingolipid Activator PrO[S]teINs.[6] Each domain of the precursor protein is approximately 80 amino acid residues long with nearly identical placement of cysteine residues and glycosylation sites. Saposins A-D localize primarily to the lysosomal compartment where they facilitate the catabolism of glycosphingolipids with short oligosaccharide groups. The precursor protein exists both as a secretory protein and as an integral membrane protein and has neurotrophic activities.[5]
Saposins A–D are required for the hydrolysis of certain sphingolipids by specific lysosomal hydrolases.[7]
Saposin A was identified as an N-terminal domain in the prosaposin cDNA prior to its isolation. It is known to stimulate the enzymatic hydrolysis of 4-methylumbelliferyl-β-glucoside, glucocerebroside, and galactocerebroside.[8]
Saposin B was the first to be discovered and was found to be required as a heat-stable factor for hydrolysis of sulfatides by arylsulfatase A. It is known by many different names, such as, sphingolipid activator protein-1 (SAP-1), sulfatide activator protein, GM1 ganglioside activator, dispersin, and nonspecific.[9] It has been observed that this particular saposin activates many enzymes through interaction with the substrates not the enzymes themselves.
Saposin C was the second saposin to be discovered and stimulates the hydrolysis of glycocerebroside by glycosylceramidase and galactocerebroside by galactosylceramidase.
Saposin D is not well known to due lack of investigation at this point in time. It was predicted from the cDNA sequence of prosaposin, like saposin A. Enzymatic stimulation is very specific for this particular glycoprotein and it not understood completely.[7]
GM2A (GM2 ganglioside activator) has been viewed as a member of the SAP family and has been called SAP-3 (sphingolipid activator protein 3)[10]
Every saposin contains about 80 amino acid residues and has six equally placed cysteines, two prolines, and a glycosylation site (two in saposin A, one each in saposins B, C, and D).[7] Since saposins characteristics of extreme heat-stability, abundance of disulfide linkages, and resistance to most proteases, they are assumed to be extremely compact and rigidly disulfide-linked molecules. Each saposin has an α-helical structure that is seen as being important for stimulation because this structure is maximal at a pH of 4.5; which is optimal for many lysosomal hydrolases.[7] This helical structure is seen in all (especially with the first region), but saposin has been predicted to have β-sheet configuration due to it first 24 amino acids of the N-end.[9]
Function
They probably act by isolating the lipid substrate from the membrane surroundings, thus making it more accessible to the soluble degradative enzymes. which contains four Saposin-B domains, yielding the active saposins after proteolytic cleavage, and two Saposin-A domains that are removed in the activation reaction. The Saposin-B domains also occur in other proteins, many of them active in the lysis of membranes.[14][15]
^ abMorimoto S, Yamamoto Y, O'Brien JS, Kishimoto Y (May 1990). "Distribution of saposin proteins (sphingolipid activator proteins) in lysosomal storage and other diseases". Proc. Natl. Acad. Sci. U.S.A. 87 (9): 3493–7. Bibcode:1990PNAS...87.3493M. doi:10.1073/pnas.87.9.3493. PMC53927. PMID 2110365.
^ abcdKishimoto Y, Hiraiwa M, O'Brien JS (September 1992). "Saposins: structure, function, distribution, and molecular genetics". J. Lipid Res. 33 (9): 1255–67. doi:10.1016/S0022-2275(20)40540-1. PMID 1402395.
^Morimoto S, Martin BM, Yamamoto Y, Kretz KA, O'Brien JS, Kishimoto Y (May 1989). "Saposin A: second cerebrosidase activator protein". Proc. Natl. Acad. Sci. U.S.A. 86 (9): 3389–93. Bibcode:1989PNAS...86.3389M. doi:10.1073/pnas.86.9.3389. PMC287138. PMID 2717620.
^ abO'Brien JS, Kishimoto Y (March 1991). "Saposin proteins: structure, function, and role in human lysosomal storage disorders". FASEB J. 5 (3): 301–8. doi:10.1096/fasebj.5.3.2001789. PMID 2001789. S2CID 40251569.
^Ahn VE, Leyko P, Alattia JR, Chen L, Privé GG (August 2006). "Crystal structures of saposins A and C". Protein Sci. 15 (8): 1849–57. doi:10.1110/ps.062256606. PMC2242594. PMID 16823039.
^Ahn VE, Faull KF, Whitelegge JP, Fluharty AL, Privé GG (January 2003). "Crystal structure of saposin B reveals a dimeric shell for lipid binding". Proc. Natl. Acad. Sci. U.S.A. 100 (1): 38–43. Bibcode:2003PNAS..100...38A. doi:10.1073/pnas.0136947100. PMC140876. PMID 12518053.
^ abRossmann M, Schultz-Heienbrok R, Behlke J, Remmel N, Alings C, Sandhoff K, Saenger W, Maier T (May 2008). "Crystal structures of human saposins C and D: implications for lipid recognition and membrane interactions". Structure. 16 (5): 809–17. doi:10.1016/j.str.2008.02.016. PMID 18462685.
^Ponting CP (1994). "Acid sphingomyelinase possesses a domain homologous to its activator proteins: saposins B and D". Protein Sci. 3 (2): 359–361. doi:10.1002/pro.5560030219. PMC2142785. PMID 8003971.
^Hofmann K, Tschopp J (1996). "Cytotoxic T cells: more weapons for new targets?". Trends Microbiol. 4 (3): 91–94. doi:10.1016/0966-842X(96)81522-8. PMID 8868085.
Further reading
Gieselmann V, Zlotogora J, Harris A, et al. (1995). "Molecular genetics of metachromatic leukodystrophy". Hum. Mutat. 4 (4): 233–42. doi:10.1002/humu.1380040402. PMID 7866401. S2CID 23519007.
Schnabel D, Schröder M, Fürst W, et al. (1992). "Simultaneous deficiency of sphingolipid activator proteins 1 and 2 is caused by a mutation in the initiation codon of their common gene". J. Biol. Chem. 267 (5): 3312–5. doi:10.1016/S0021-9258(19)50733-5. PMID 1371116.
Hiraiwa M, Soeda S, Kishimoto Y, O'Brien JS (1993). "Binding and transport of gangliosides by prosaposin". Proc. Natl. Acad. Sci. U.S.A. 89 (23): 11254–8. doi:10.1073/pnas.89.23.11254. PMC50528. PMID 1454804.
Rorman EG, Scheinker V, Grabowski GA (1992). "Structure and evolution of the human prosaposin chromosomal gene". Genomics. 13 (2): 312–8. doi:10.1016/0888-7543(92)90247-P. PMID 1612590.
Kondoh K, Hineno T, Sano A, Kakimoto Y (1992). "Isolation and characterization of prosaposin from human milk". Biochem. Biophys. Res. Commun. 181 (1): 286–92. doi:10.1016/S0006-291X(05)81415-9. PMID 1958198.
Holtschmidt H, Sandhoff K, Fürst W, et al. (1991). "The organization of the gene for the human cerebroside sulfate activator protein". FEBS Lett. 280 (2): 267–70. doi:10.1016/0014-5793(91)80308-P. PMID 2013321. S2CID 38952277.
Holtschmidt H, Sandhoff K, Kwon HY, et al. (1991). "Sulfatide activator protein. Alternative splicing that generates three mRNAs and a newly found mutation responsible for a clinical disease". J. Biol. Chem. 266 (12): 7556–60. doi:10.1016/S0021-9258(20)89483-6. PMID 2019586.
Hineno T, Sano A, Kondoh K, et al. (1991). "Secretion of sphingolipid hydrolase activator precursor, prosaposin". Biochem. Biophys. Res. Commun. 176 (2): 668–74. doi:10.1016/S0006-291X(05)80236-0. PMID 2025281.
Schnabel D, Schröder M, Sandhoff K (1991). "Mutation in the sphingolipid activator protein 2 in a patient with a variant of Gaucher disease". FEBS Lett. 284 (1): 57–9. doi:10.1016/0014-5793(91)80760-Z. PMID 2060627. S2CID 42681055.
Zhang XL, Rafi MA, DeGala G, Wenger DA (1991). "The mechanism for a 33-nucleotide insertion in mRNA causing sphingolipid activator protein (SAP-1)-deficient metachromatic leukodystrophy". Hum. Genet. 87 (2): 211–5. doi:10.1007/BF00204185. PMID 2066109. S2CID 23791396.
Fürst W, Schubert J, Machleidt W, et al. (1990). "The complete amino-acid sequences of human ganglioside GM2 activator protein and cerebroside sulfate activator protein". Eur. J. Biochem. 192 (3): 709–14. doi:10.1111/j.1432-1033.1990.tb19280.x. PMID 2209618.
Rafi MA, Zhang XL, DeGala G, Wenger DA (1990). "Detection of a point mutation in sphingolipid activator protein-1 mRNA in patients with a variant form of metachromatic leukodystrophy". Biochem. Biophys. Res. Commun. 166 (2): 1017–23. doi:10.1016/0006-291X(90)90912-7. PMID 2302219.
Kretz KA, Carson GS, Morimoto S, et al. (1990). "Characterization of a mutation in a family with saposin B deficiency: a glycosylation site defect". Proc. Natl. Acad. Sci. U.S.A. 87 (7): 2541–4. Bibcode:1990PNAS...87.2541K. doi:10.1073/pnas.87.7.2541. PMC53725. PMID 2320574.
Nakano T, Sandhoff K, Stümper J, et al. (1989). "Structure of full-length cDNA coding for sulfatide activator, a Co-beta-glucosidase and two other homologous proteins: two alternate forms of the sulfatide activator". J. Biochem. 105 (2): 152–4. doi:10.1093/oxfordjournals.jbchem.a122629. PMID 2498298.
Rorman EG, Grabowski GA (1990). "Molecular cloning of a human co-beta-glucosidase cDNA: evidence that four sphingolipid hydrolase activator proteins are encoded by single genes in humans and rats". Genomics. 5 (3): 486–92. doi:10.1016/0888-7543(89)90014-1. PMID 2515150.
Morimoto S, Martin BM, Yamamoto Y, et al. (1989). "Saposin A: second cerebrosidase activator protein". Proc. Natl. Acad. Sci. U.S.A. 86 (9): 3389–93. Bibcode:1989PNAS...86.3389M. doi:10.1073/pnas.86.9.3389. PMC287138. PMID 2717620.
Dewji NN, Wenger DA, O'Brien JS (1988). "Nucleotide sequence of cloned cDNA for human sphingolipid activator protein 1 precursor". Proc. Natl. Acad. Sci. U.S.A. 84 (23): 8652–6. doi:10.1073/pnas.84.23.8652. PMC299604. PMID 2825202.
O'Brien JS, Kretz KA, Dewji N, et al. (1988). "Coding of two sphingolipid activator proteins (SAP-1 and SAP-2) by same genetic locus". Science. 241 (4869): 1098–101. Bibcode:1988Sci...241.1098O. doi:10.1126/science.2842863. PMID 2842863.
Morimoto S, Martin BM, Kishimoto Y, O'Brien JS (1988). "Saposin D: a sphingomyelinase activator". Biochem. Biophys. Res. Commun. 156 (1): 403–10. doi:10.1016/S0006-291X(88)80855-6. PMID 2845979.
Dewji N, Wenger D, Fujibayashi S, et al. (1986). "Molecular cloning of the sphingolipid activator protein-1 (SAP-1), the sulfatide sulfatase activator". Biochem. Biophys. Res. Commun. 134 (2): 989–94. doi:10.1016/S0006-291X(86)80518-6. PMID 2868718.
prosaposin, also, known, psap, protein, which, humans, encoded, psap, gene, psapavailable, structurespdbortholog, search, pdbe, rcsblist, codes1m12, 1n69, 1sn6, 2dob, 2gtg, 2qyp, 2r0r, 2r1q, 2rb3, 2z9a, 3bqp, 3bqq, 4ddj, 4uex, 4v2oidentifiersaliasespsap, glba,. Prosaposin also known as PSAP is a protein which in humans is encoded by the PSAP gene 5 PSAPAvailable structuresPDBOrtholog search PDBe RCSBList of PDB id codes1M12 1N69 1SN6 2DOB 2GTG 2QYP 2R0R 2R1Q 2RB3 2Z9A 3BQP 3BQQ 4DDJ 4UEX 4V2OIdentifiersAliasesPSAP GLBA SAP1 prosaposin SAP2 PSAPD PARK24External IDsOMIM 176801 MGI 97783 HomoloGene 37680 GeneCards PSAPGene location Human Chr Chromosome 10 human 1 Band10q22 1Start71 816 298 bp 1 End71 851 251 bp 1 Gene location Mouse Chr Chromosome 10 mouse 2 Band10 B4 10 30 02 cMStart60 113 449 bp 2 End60 138 376 bp 2 RNA expression patternBgeeHumanMouse ortholog Top expressed inmonocytegallbladderinternal globus pallidusstromal cell of endometriumAchilles tendonLeft adrenal glandvisceral pleuraprefrontal cortexoptic nervecerebellar hemisphereTop expressed insuperior frontal gyruscerebellar cortexcalvariautricleventromedial nucleuscerebellar vermisdorsomedial hypothalamic nucleusmammillary bodylateral hypothalamusmucosa of urinary bladderMore reference expression dataBioGPSMore reference expression dataGene ontologyMolecular functionG protein coupled receptor binding protein binding lipid binding enzyme activator activity beta galactosidase activity phospholipid binding protein homodimerization activity ganglioside GM1 binding ganglioside GM2 binding ganglioside GM3 binding ganglioside GT1b binding ganglioside GP1c binding identical protein binding protease bindingCellular componentlysosomal membrane integral component of membrane mitochondrion lysosomal lumen extracellular exosome extracellular space lysosome plasma membrane azurophil granule membrane intracellular membrane bounded organelle extracellular matrix extracellular region cytoplasm collagen containing extracellular matrix late endosomeBiological processlipid metabolism lipid transport epithelial cell differentiation involved in prostate gland development regulation of MAPK cascade glycosphingolipid metabolic process developmental growth adenylate cyclase inhibiting G protein coupled receptor signaling pathway regulation of autophagy positive regulation of MAPK cascade cellular response to organic substance negative regulation of hydrogen peroxide induced cell death regulation of lipid metabolic process prostate gland growth platelet degranulation sphingolipid metabolic process positive regulation of catalytic activity neutrophil degranulation ganglioside GM1 transport to membrane corneocyte development galactosylceramide catabolic process G protein coupled receptor signaling pathway sensory perception of sound myelination neuromuscular process controlling balance positive regulation of hydrolase activity urination cochlea development walking behavior cornified envelope assembly lysosomal transportSources Amigo QuickGOOrthologsSpeciesHumanMouseEntrez566019156EnsemblENSG00000197746ENSMUSG00000004207UniProtP07602Q5BJH1Q61207RefSeq mRNA NM 002778NM 001042465NM 001042466NM 001146120NM 001146121NM 001146122NM 001146123NM 001146124NM 011179RefSeq protein NP 001035930NP 001035931NP 002769NP 002769 1NP 001139592NP 001139593NP 001139594NP 001139595NP 001139596NP 035309Location UCSC Chr 10 71 82 71 85 MbChr 10 60 11 60 14 MbPubMed search 3 4 WikidataView Edit HumanView Edit MouseThis highly conserved glycoprotein is a precursor for 4 cleavage products saposins A B C and D Saposin is an acronym for Sphingolipid Activator PrO S teINs 6 Each domain of the precursor protein is approximately 80 amino acid residues long with nearly identical placement of cysteine residues and glycosylation sites Saposins A D localize primarily to the lysosomal compartment where they facilitate the catabolism of glycosphingolipids with short oligosaccharide groups The precursor protein exists both as a secretory protein and as an integral membrane protein and has neurotrophic activities 5 Saposins A D are required for the hydrolysis of certain sphingolipids by specific lysosomal hydrolases 7 Contents 1 Family members 2 Structure 3 Function 4 Clinical significance 5 See also 6 References 7 Further reading 8 External linksFamily members EditSaposin A was identified as an N terminal domain in the prosaposin cDNA prior to its isolation It is known to stimulate the enzymatic hydrolysis of 4 methylumbelliferyl b glucoside glucocerebroside and galactocerebroside 8 Saposin B was the first to be discovered and was found to be required as a heat stable factor for hydrolysis of sulfatides by arylsulfatase A It is known by many different names such as sphingolipid activator protein 1 SAP 1 sulfatide activator protein GM1 ganglioside activator dispersin and nonspecific 9 It has been observed that this particular saposin activates many enzymes through interaction with the substrates not the enzymes themselves Saposin C was the second saposin to be discovered and stimulates the hydrolysis of glycocerebroside by glycosylceramidase and galactocerebroside by galactosylceramidase Saposin D is not well known to due lack of investigation at this point in time It was predicted from the cDNA sequence of prosaposin like saposin A Enzymatic stimulation is very specific for this particular glycoprotein and it not understood completely 7 GM2A GM2 ganglioside activator has been viewed as a member of the SAP family and has been called SAP 3 sphingolipid activator protein 3 10 Crystal structures of human saposins A D Saposin A PDB 2DOB 11 Saposin B PDB 1N69 12 Saposin C dimer in an open conformation PDB 2QYP 13 Saposin D PDB 2RB3 13 Structure EditEvery saposin contains about 80 amino acid residues and has six equally placed cysteines two prolines and a glycosylation site two in saposin A one each in saposins B C and D 7 Since saposins characteristics of extreme heat stability abundance of disulfide linkages and resistance to most proteases they are assumed to be extremely compact and rigidly disulfide linked molecules Each saposin has an a helical structure that is seen as being important for stimulation because this structure is maximal at a pH of 4 5 which is optimal for many lysosomal hydrolases 7 This helical structure is seen in all especially with the first region but saposin has been predicted to have b sheet configuration due to it first 24 amino acids of the N end 9 Function EditThey probably act by isolating the lipid substrate from the membrane surroundings thus making it more accessible to the soluble degradative enzymes which contains four Saposin B domains yielding the active saposins after proteolytic cleavage and two Saposin A domains that are removed in the activation reaction The Saposin B domains also occur in other proteins many of them active in the lysis of membranes 14 15 Clinical significance EditMutations in this gene have been associated with Gaucher disease Tay Sachs disease and metachromatic leukodystrophy 6 See also EditSaposin protein domainReferences Edit a b c GRCh38 Ensembl release 89 ENSG00000197746 Ensembl May 2017 a b c GRCm38 Ensembl release 89 ENSMUSG00000004207 Ensembl May 2017 Human PubMed Reference National Center for Biotechnology Information U S National Library of Medicine Mouse PubMed Reference National Center for Biotechnology Information U S National Library of Medicine a b Entrez Gene PSAP prosaposin variant Gaucher disease and variant metachromatic leukodystrophy a b Morimoto S Yamamoto Y O Brien JS Kishimoto Y May 1990 Distribution of saposin proteins sphingolipid activator proteins in lysosomal storage and other diseases Proc Natl Acad Sci U S A 87 9 3493 7 Bibcode 1990PNAS 87 3493M doi 10 1073 pnas 87 9 3493 PMC 53927 PMID 2110365 a b c d Kishimoto Y Hiraiwa M O Brien JS September 1992 Saposins structure function distribution and molecular genetics J Lipid Res 33 9 1255 67 doi 10 1016 S0022 2275 20 40540 1 PMID 1402395 Morimoto S Martin BM Yamamoto Y Kretz KA O Brien JS Kishimoto Y May 1989 Saposin A second cerebrosidase activator protein Proc Natl Acad Sci U S A 86 9 3389 93 Bibcode 1989PNAS 86 3389M doi 10 1073 pnas 86 9 3389 PMC 287138 PMID 2717620 a b O Brien JS Kishimoto Y March 1991 Saposin proteins structure function and role in human lysosomal storage disorders FASEB J 5 3 301 8 doi 10 1096 fasebj 5 3 2001789 PMID 2001789 S2CID 40251569 HUGO Gene Nomenclature Committee GM2A HGNC database retrieved 2016 03 13 Ahn VE Leyko P Alattia JR Chen L Prive GG August 2006 Crystal structures of saposins A and C Protein Sci 15 8 1849 57 doi 10 1110 ps 062256606 PMC 2242594 PMID 16823039 Ahn VE Faull KF Whitelegge JP Fluharty AL Prive GG January 2003 Crystal structure of saposin B reveals a dimeric shell for lipid binding Proc Natl Acad Sci U S A 100 1 38 43 Bibcode 2003PNAS 100 38A doi 10 1073 pnas 0136947100 PMC 140876 PMID 12518053 a b Rossmann M Schultz Heienbrok R Behlke J Remmel N Alings C Sandhoff K Saenger W Maier T May 2008 Crystal structures of human saposins C and D implications for lipid recognition and membrane interactions Structure 16 5 809 17 doi 10 1016 j str 2008 02 016 PMID 18462685 Ponting CP 1994 Acid sphingomyelinase possesses a domain homologous to its activator proteins saposins B and D Protein Sci 3 2 359 361 doi 10 1002 pro 5560030219 PMC 2142785 PMID 8003971 Hofmann K Tschopp J 1996 Cytotoxic T cells more weapons for new targets Trends Microbiol 4 3 91 94 doi 10 1016 0966 842X 96 81522 8 PMID 8868085 Further reading EditGieselmann V Zlotogora J Harris A et al 1995 Molecular genetics of metachromatic leukodystrophy Hum Mutat 4 4 233 42 doi 10 1002 humu 1380040402 PMID 7866401 S2CID 23519007 Schnabel D Schroder M Furst W et al 1992 Simultaneous deficiency of sphingolipid activator proteins 1 and 2 is caused by a mutation in the initiation codon of their common gene J Biol Chem 267 5 3312 5 doi 10 1016 S0021 9258 19 50733 5 PMID 1371116 Hiraiwa M Soeda S Kishimoto Y O Brien JS 1993 Binding and transport of gangliosides by prosaposin Proc Natl Acad Sci U S A 89 23 11254 8 doi 10 1073 pnas 89 23 11254 PMC 50528 PMID 1454804 Rorman EG Scheinker V Grabowski GA 1992 Structure and evolution of the human prosaposin chromosomal gene Genomics 13 2 312 8 doi 10 1016 0888 7543 92 90247 P PMID 1612590 Kondoh K Hineno T Sano A Kakimoto Y 1992 Isolation and characterization of prosaposin from human milk Biochem Biophys Res Commun 181 1 286 92 doi 10 1016 S0006 291X 05 81415 9 PMID 1958198 Holtschmidt H Sandhoff K Furst W et al 1991 The organization of the gene for the human cerebroside sulfate activator protein FEBS Lett 280 2 267 70 doi 10 1016 0014 5793 91 80308 P PMID 2013321 S2CID 38952277 Holtschmidt H Sandhoff K Kwon HY et al 1991 Sulfatide activator protein Alternative splicing that generates three mRNAs and a newly found mutation responsible for a clinical disease J Biol Chem 266 12 7556 60 doi 10 1016 S0021 9258 20 89483 6 PMID 2019586 Hineno T Sano A Kondoh K et al 1991 Secretion of sphingolipid hydrolase activator precursor prosaposin Biochem Biophys Res Commun 176 2 668 74 doi 10 1016 S0006 291X 05 80236 0 PMID 2025281 Schnabel D Schroder M Sandhoff K 1991 Mutation in the sphingolipid activator protein 2 in a patient with a variant of Gaucher disease FEBS Lett 284 1 57 9 doi 10 1016 0014 5793 91 80760 Z PMID 2060627 S2CID 42681055 Zhang XL Rafi MA DeGala G Wenger DA 1991 The mechanism for a 33 nucleotide insertion in mRNA causing sphingolipid activator protein SAP 1 deficient metachromatic leukodystrophy Hum Genet 87 2 211 5 doi 10 1007 BF00204185 PMID 2066109 S2CID 23791396 Furst W Schubert J Machleidt W et al 1990 The complete amino acid sequences of human ganglioside GM2 activator protein and cerebroside sulfate activator protein Eur J Biochem 192 3 709 14 doi 10 1111 j 1432 1033 1990 tb19280 x PMID 2209618 Rafi MA Zhang XL DeGala G Wenger DA 1990 Detection of a point mutation in sphingolipid activator protein 1 mRNA in patients with a variant form of metachromatic leukodystrophy Biochem Biophys Res Commun 166 2 1017 23 doi 10 1016 0006 291X 90 90912 7 PMID 2302219 Kretz KA Carson GS Morimoto S et al 1990 Characterization of a mutation in a family with saposin B deficiency a glycosylation site defect Proc Natl Acad Sci U S A 87 7 2541 4 Bibcode 1990PNAS 87 2541K doi 10 1073 pnas 87 7 2541 PMC 53725 PMID 2320574 Nakano T Sandhoff K Stumper J et al 1989 Structure of full length cDNA coding for sulfatide activator a Co beta glucosidase and two other homologous proteins two alternate forms of the sulfatide activator J Biochem 105 2 152 4 doi 10 1093 oxfordjournals jbchem a122629 PMID 2498298 Rorman EG Grabowski GA 1990 Molecular cloning of a human co beta glucosidase cDNA evidence that four sphingolipid hydrolase activator proteins are encoded by single genes in humans and rats Genomics 5 3 486 92 doi 10 1016 0888 7543 89 90014 1 PMID 2515150 Morimoto S Martin BM Yamamoto Y et al 1989 Saposin A second cerebrosidase activator protein Proc Natl Acad Sci U S A 86 9 3389 93 Bibcode 1989PNAS 86 3389M doi 10 1073 pnas 86 9 3389 PMC 287138 PMID 2717620 Dewji NN Wenger DA O Brien JS 1988 Nucleotide sequence of cloned cDNA for human sphingolipid activator protein 1 precursor Proc Natl Acad Sci U S A 84 23 8652 6 doi 10 1073 pnas 84 23 8652 PMC 299604 PMID 2825202 O Brien JS Kretz KA Dewji N et al 1988 Coding of two sphingolipid activator proteins SAP 1 and SAP 2 by same genetic locus Science 241 4869 1098 101 Bibcode 1988Sci 241 1098O doi 10 1126 science 2842863 PMID 2842863 Morimoto S Martin BM Kishimoto Y O Brien JS 1988 Saposin D a sphingomyelinase activator Biochem Biophys Res Commun 156 1 403 10 doi 10 1016 S0006 291X 88 80855 6 PMID 2845979 Dewji N Wenger D Fujibayashi S et al 1986 Molecular cloning of the sphingolipid activator protein 1 SAP 1 the sulfatide sulfatase activator Biochem Biophys Res Commun 134 2 989 94 doi 10 1016 S0006 291X 86 80518 6 PMID 2868718 External links EditSaposins at the US National Library of Medicine Medical Subject Headings MeSH Retrieved from https en wikipedia org w index php title Prosaposin amp oldid 1136198479, wikipedia, wiki, book, books, library,
