An enterotoxin is a proteinexotoxin released by a microorganism that targets the intestines.[1] They can be chromosomally or plasmid encoded.[2] They are heat labile (>60⁰), of low molecular weight and water-soluble. Enterotoxins are frequently cytotoxic and kill cells by altering the apical membrane permeability of the mucosal (epithelial) cells of the intestinal wall. They are mostly pore-forming toxins (mostly chloride pores), secreted by bacteria, that assemble to form pores in cell membranes. This causes the cells to die.
Staph/Strep enterotoxin, C terminal
identification of a secondary zinc-binding site in staphylococcal enterotoxin c2: implications for superantigen recognition
Enterotoxins have a particularly marked effect upon the gastrointestinal tract, causing traveler's diarrhea and food poisoning. The action of enterotoxins leads to increased chloride ion permeability of the apical membrane of intestinal mucosal cells. These membrane pores are activated either by increased cAMP or by increased calcium ion concentration intracellularly. The pore formation has a direct effect on the osmolarity of the luminal contents of the intestines. Increased chloride permeability leads to leakage into the lumen followed by sodium and water movement. This leads to a secretory diarrhea within a few hours of ingesting enterotoxin. Several microbial organisms contain the necessary enterotoxin to create such an effect, such as Staphylococcus aureus and E. coli.[3]
The drug linaclotide, used to treat some forms of constipation, is based on the mechanism of enterotoxins.[3]
Classification and 3D structuresedit
Bacterialedit
Enterotoxins can be formed by the bacterial pathogens Staphylococcus aureus and Bacillus cereus and can cause Staphylococcal Food Poisoning and Bacillus cereus diarrheal disease, respectively. Staphylococcal enterotoxins and streptococcal exotoxins constitute a family of biologically and structurally related pyrogenic superantigens.[4] 25 staphylococcal enterotoxins (SEs), mainly produced by Staphylococcus aureus, have been identified to date and named alphabetically (SEA - SEZ).[5] It has been suggested that staphylococci other than S. aureus can contribute to Staphylococcal Food Poisoning by forming enterotoxins.[6] Streptococcal exotoxins are produced by Streptococcus pyogenes.[7][8] These toxins share the ability to bind to the major histocompatibility complex proteins of their hosts. A more distant relative of the family is the S. aureus toxic shock syndrome toxin, which shares only a low level of sequence similarity with this group.
All of these toxins share a similar two-domain fold (N and C-terminal domains) with a long alpha-helix in the middle of the molecule, a characteristic beta-barrel known as the "oligosaccharide/oligonucleotide fold" at the N-terminal domain and a beta-grasp motif at the C-terminal domain. An example is staphylococcal enterotoxin B. Each superantigen possesses slightly different binding mode(s) when it interacts with MHC class II molecules or the T-cell receptor.[9]
Viruses in the families Reoviridae, Caliciviridae, and Astroviridae are responsible for a huge percentage of gastrointestinal disease worldwide. Rotaviruses (of Reoviridae) have been found to contain an enterotoxin which plays a role in viral pathogenesis. NSP4, is a protein that is made during the intracellular phase of the virion's life cycle and is known to have a primary function in intracellular virion maturation.[13] However, when NSP4 from group A Rotaviruses was purified (4 alleles tested), concentrated, and injected into a mouse model, diarrheal disease mimicking that caused by Rotavirus infection commenced.[14] A putative mode of toxicity is that NSP4 activates a signal transduction pathway that ultimately results in an increased cellular concentration of calcium and subsequent chloride secretion from the cell.[15] Secretion of ions from villi lining the gut alter normal osmotic pressures and prevent uptake of water, eventually causing diarrhea.
^Carlton Gyles, Magdalene So, Stanley Falkow, Journal of Infectious Diseases (1974) 130 (1): 40-49.
^ abHornby, PJ (2015). "Drug discovery approaches to irritable bowel syndrome". Expert Opinion on Drug Discovery. 10 (8): 809–24. doi:10.1517/17460441.2015.1049528. PMID 26193876. S2CID 207494271.
^Dinges, M. M.; Orwin, P. M.; Schlievert, P. M. (2000). "Exotoxins of Staphylococcus aureus". Clinical Microbiology Reviews. 13 (1): 16–34, table of contents. doi:10.1128/CMR.13.1.16. ISSN 0893-8512. PMC88931. PMID 10627489.
^Etter, Danai; Schelin, Jenny; Schuppler, Markus; Johler, Sophia (2020-09-10). "Staphylococcal Enterotoxin C—An Update on SEC Variants, Their Structure and Properties, and Their Role in Foodborne Intoxications". Toxins. 12 (9): 584. doi:10.3390/toxins12090584. hdl:20.500.11850/441345. PMC7551944. PMID 32927913.
^Fetsch, Alexandra; Johler, Sophia (2018-04-27). "Staphylococcus aureus as a Foodborne Pathogen". Current Clinical Microbiology Reports. 5 (2): 88–96. doi:10.1007/s40588-018-0094-x. ISSN 2196-5471. S2CID 13668423.
^Iandolo JJ (1989). "Genetic analysis of extracellular toxins of Staphylococcus aureus". Annu. Rev. Microbiol. 43: 375–402. doi:10.1146/annurev.mi.43.100189.002111. PMID 2679358.
^Marrack P, Kappler J (May 1990). "The staphylococcal enterotoxins and their relatives". Science. 248 (4956): 705–11. Bibcode:1990Sci...248..705M. doi:10.1126/science.2185544. PMID 2185544. S2CID 33752378.
^Papageorgiou AC, Tranter HS, Acharya KR (March 1998). "Crystal structure of microbial superantigen staphylococcal enterotoxin B at 1.5 A resolution: implications for superantigen recognition by MHC class II molecules and T-cell receptors". J. Mol. Biol. 277 (1): 61–79. doi:10.1006/jmbi.1997.1577. PMID 9514739.
^Katahira J, Sugiyama H, Inoue N, Horiguchi Y, Matsuda M, Sugimoto N (October 1997). "Clostridium perfringens enterotoxin utilizes two structurally related membrane proteins as functional receptors in vivo". The Journal of Biological Chemistry. 272 (42): 26652–8. doi:10.1074/jbc.272.42.26652. PMID 9334247.
^CBRNE - Staphylococcal Enterotoxin B at eMedicine
^Crawford, Sue E.; Ramani, Sasirekha; Tate, Jacqueline E.; Parashar, Umesh D.; Svensson, Lennart; Hagbom, Marie; Franco, Manuel A.; Greenberg, Harry B.; O'Ryan, Miguel; Kang, Gagandeep; Desselberger, Ulrich; Estes, Mary K. (9 November 2017). "Rotavirus infection". Nature Reviews Disease Primers. 3 (1): 17083. doi:10.1038/nrdp.2017.83. PMC5858916. PMID 29119972.
^Horie, Y.; Nakagomi, O.; Koshimura, Y.; Nakagomi, T.; Suzuki, Y.; Oka, T.; Sasaki, S.; Matsuda, Y.; Watanabe, S. (September 1999). "Diarrhea Induction by Rotavirus NSP4 in the Homologous Mouse Model System". Virology. 262 (2): 398–407. doi:10.1006/viro.1999.9912. PMID 10502518.
^Zhang, Mingdong; Zeng, Carl Q.-Y.; Morris, Andrew P.; Estes, Mary K. (15 December 2000). "A Functional NSP4 Enterotoxin Peptide Secreted from Rotavirus-Infected Cells". Journal of Virology. 74 (24): 11663–11670. doi:10.1128/JVI.74.24.11663-11670.2000. PMC112448. PMID 11090165.
External linksedit
Alfonse T. Masi; Rafael A. Timothee; Rolando Armijo; Darwin Alonso; Luis E. Mainardi (Mar 1959). "Two poisoning outbreaks in Puerto Rico from salt preserved codfish". Public Health Rep. 74 (3): 265–270. doi:10.2307/4590423. JSTOR 4590423. PMC1929208. PMID 13634314.
This article incorporates text from the public domain Pfam and InterPro: IPR006123
April 13, 2024
enterotoxin, enterotoxin, protein, exotoxin, released, microorganism, that, targets, intestines, they, chromosomally, plasmid, encoded, they, heat, labile, molecular, weight, water, soluble, frequently, cytotoxic, kill, cells, altering, apical, membrane, perme. An enterotoxin is a protein exotoxin released by a microorganism that targets the intestines 1 They can be chromosomally or plasmid encoded 2 They are heat labile gt 60 of low molecular weight and water soluble Enterotoxins are frequently cytotoxic and kill cells by altering the apical membrane permeability of the mucosal epithelial cells of the intestinal wall They are mostly pore forming toxins mostly chloride pores secreted by bacteria that assemble to form pores in cell membranes This causes the cells to die Staph Strep enterotoxin C terminalidentification of a secondary zinc binding site in staphylococcal enterotoxin c2 implications for superantigen recognitionIdentifiersSymbolStap Strp tox CPfamPF02876Pfam clanCL0386InterProIPR006123PROSITEPDOC00250SCOP21se3 SCOPe SUPFAMOPM superfamily364OPM protein1dyqAvailable protein structures Pfam structures ECOD PDBRCSB PDB PDBe PDBjPDBsumstructure summary Contents 1 Clinical significance 2 Classification and 3D structures 2 1 Bacterial 2 2 Viral 3 See also 4 References 5 External linksClinical significance editEnterotoxins have a particularly marked effect upon the gastrointestinal tract causing traveler s diarrhea and food poisoning The action of enterotoxins leads to increased chloride ion permeability of the apical membrane of intestinal mucosal cells These membrane pores are activated either by increased cAMP or by increased calcium ion concentration intracellularly The pore formation has a direct effect on the osmolarity of the luminal contents of the intestines Increased chloride permeability leads to leakage into the lumen followed by sodium and water movement This leads to a secretory diarrhea within a few hours of ingesting enterotoxin Several microbial organisms contain the necessary enterotoxin to create such an effect such as Staphylococcus aureus and E coli 3 The drug linaclotide used to treat some forms of constipation is based on the mechanism of enterotoxins 3 Classification and 3D structures editBacterial edit Enterotoxins can be formed by the bacterial pathogens Staphylococcus aureus and Bacillus cereus and can cause Staphylococcal Food Poisoning and Bacillus cereus diarrheal disease respectively Staphylococcal enterotoxins and streptococcal exotoxins constitute a family of biologically and structurally related pyrogenic superantigens 4 25 staphylococcal enterotoxins SEs mainly produced by Staphylococcus aureus have been identified to date and named alphabetically SEA SEZ 5 It has been suggested that staphylococci other than S aureus can contribute to Staphylococcal Food Poisoning by forming enterotoxins 6 Streptococcal exotoxins are produced by Streptococcus pyogenes 7 8 These toxins share the ability to bind to the major histocompatibility complex proteins of their hosts A more distant relative of the family is the S aureustoxic shock syndrome toxin which shares only a low level of sequence similarity with this group All of these toxins share a similar two domain fold N and C terminal domains with a long alpha helix in the middle of the molecule a characteristic beta barrel known as the oligosaccharide oligonucleotide fold at the N terminal domain and a beta grasp motif at the C terminal domain An example is staphylococcal enterotoxin B Each superantigen possesses slightly different binding mode s when it interacts with MHC class II molecules or the T cell receptor 9 The beta grasp domain has some structural similarities to the beta grasp motif present in immunoglobulin binding domains ubiquitin 2Fe 2 S ferredoxin and translation initiation factor 3 as identified by the SCOP database Clostridium difficile Clostridium perfringens Clostridium enterotoxin 10 Vibrio cholerae Cholera toxin 11 Staphylococcus aureus Staphylococcal enterotoxin B 12 Yersinia enterocolitica Shigella dysenteriae Shiga toxin 11 Viral edit Viruses in the families Reoviridae Caliciviridae and Astroviridae are responsible for a huge percentage of gastrointestinal disease worldwide Rotaviruses of Reoviridae have been found to contain an enterotoxin which plays a role in viral pathogenesis NSP4 is a protein that is made during the intracellular phase of the virion s life cycle and is known to have a primary function in intracellular virion maturation 13 However when NSP4 from group A Rotaviruses was purified 4 alleles tested concentrated and injected into a mouse model diarrheal disease mimicking that caused by Rotavirus infection commenced 14 A putative mode of toxicity is that NSP4 activates a signal transduction pathway that ultimately results in an increased cellular concentration of calcium and subsequent chloride secretion from the cell 15 Secretion of ions from villi lining the gut alter normal osmotic pressures and prevent uptake of water eventually causing diarrhea Rotavirus NSP4 See also editEndotoxin ExotoxinReferences edit enterotoxin at Dorland s Medical Dictionary Carlton Gyles Magdalene So Stanley Falkow Journal of Infectious Diseases 1974 130 1 40 49 a b Hornby PJ 2015 Drug discovery approaches to irritable bowel syndrome Expert Opinion on Drug Discovery 10 8 809 24 doi 10 1517 17460441 2015 1049528 PMID 26193876 S2CID 207494271 Dinges M M Orwin P M Schlievert P M 2000 Exotoxins of Staphylococcus aureus Clinical Microbiology Reviews 13 1 16 34 table of contents doi 10 1128 CMR 13 1 16 ISSN 0893 8512 PMC 88931 PMID 10627489 Etter Danai Schelin Jenny Schuppler Markus Johler Sophia 2020 09 10 Staphylococcal Enterotoxin C An Update on SEC Variants Their Structure and Properties and Their Role in Foodborne Intoxications Toxins 12 9 584 doi 10 3390 toxins12090584 hdl 20 500 11850 441345 PMC 7551944 PMID 32927913 Fetsch Alexandra Johler Sophia 2018 04 27 Staphylococcus aureus as a Foodborne Pathogen Current Clinical Microbiology Reports 5 2 88 96 doi 10 1007 s40588 018 0094 x ISSN 2196 5471 S2CID 13668423 Iandolo JJ 1989 Genetic analysis of extracellular toxins of Staphylococcus aureus Annu Rev Microbiol 43 375 402 doi 10 1146 annurev mi 43 100189 002111 PMID 2679358 Marrack P Kappler J May 1990 The staphylococcal enterotoxins and their relatives Science 248 4956 705 11 Bibcode 1990Sci 248 705M doi 10 1126 science 2185544 PMID 2185544 S2CID 33752378 Papageorgiou AC Tranter HS Acharya KR March 1998 Crystal structure of microbial superantigen staphylococcal enterotoxin B at 1 5 A resolution implications for superantigen recognition by MHC class II molecules and T cell receptors J Mol Biol 277 1 61 79 doi 10 1006 jmbi 1997 1577 PMID 9514739 Katahira J Sugiyama H Inoue N Horiguchi Y Matsuda M Sugimoto N October 1997 Clostridium perfringens enterotoxin utilizes two structurally related membrane proteins as functional receptors in vivo The Journal of Biological Chemistry 272 42 26652 8 doi 10 1074 jbc 272 42 26652 PMID 9334247 a b Enterotoxins at the U S National Library of Medicine Medical Subject Headings MeSH CBRNE Staphylococcal Enterotoxin B at eMedicine Crawford Sue E Ramani Sasirekha Tate Jacqueline E Parashar Umesh D Svensson Lennart Hagbom Marie Franco Manuel A Greenberg Harry B O Ryan Miguel Kang Gagandeep Desselberger Ulrich Estes Mary K 9 November 2017 Rotavirus infection Nature Reviews Disease Primers 3 1 17083 doi 10 1038 nrdp 2017 83 PMC 5858916 PMID 29119972 Horie Y Nakagomi O Koshimura Y Nakagomi T Suzuki Y Oka T Sasaki S Matsuda Y Watanabe S September 1999 Diarrhea Induction by Rotavirus NSP4 in the Homologous Mouse Model System Virology 262 2 398 407 doi 10 1006 viro 1999 9912 PMID 10502518 Zhang Mingdong Zeng Carl Q Y Morris Andrew P Estes Mary K 15 December 2000 A Functional NSP4 Enterotoxin Peptide Secreted from Rotavirus Infected Cells Journal of Virology 74 24 11663 11670 doi 10 1128 JVI 74 24 11663 11670 2000 PMC 112448 PMID 11090165 External links editAlfonse T Masi Rafael A Timothee Rolando Armijo Darwin Alonso Luis E Mainardi Mar 1959 Two poisoning outbreaks in Puerto Rico from salt preserved codfish Public Health Rep 74 3 265 270 doi 10 2307 4590423 JSTOR 4590423 PMC 1929208 PMID 13634314 This article incorporates text from the public domain Pfam and InterPro IPR006123 Retrieved from https en wikipedia org w index php title Enterotoxin amp oldid 1216583382, wikipedia, wiki, book, books, library,
