The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains. The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility.
CD9 is a cell surface glycoprotein that is known to complex with integrins and other transmembrane 4 superfamily proteins. CD9 is found on the surface of exosomes[2][3] and it can modulate cell adhesion and migration and also trigger platelet activation and aggregation. In addition, the protein appears to promote muscle cell fusion and support myotube maintenance.[4] This protein also seems to be a key part in the egg-sperm fusion during mammalian fertilization. While oocytes are ovulated, CD9-deficient oocytes are not properly fused with sperm upon fertilization.[5] CD9 is located in the microvillar membrane of the oocytes and also appears to intervene in maintaining the normal shape of oocyte microvilli.[6]
↑Sumiyoshi N, Ishitobi H, Miyaki S, Miyado K, Adachi N, Ochi M (October 2016). "The role of tetraspanin CD9 in osteoarthritis using three different mouse models". Biomedical Research. 37 (5). doi:10.2220/biomedres.37.283. PMID27784871.
↑Le Naour F, Rubinstein E, Jasmin C, Prenant M, Boucheix C (2000). "Severely Reduced Female Fertility in CD9-Deficient Mice". Science. 287 (5451): 319–321. doi:10.1126/science.287.5451.319. PMID10634790.
↑Runge KE, Evans JE, He ZY, Gupta S, McDonald KL, Stahlberg H, Primakoff P, Myles DG (2007). "Oocyte CD9 is enriched on the microvillar membrane and required for normal microvillar shape and distribution". Developmental Biology. 304 (1): 317–325. doi:10.1016/j.ydbio.2006.12.041. PMID17239847.
↑Anzai N, Lee Y, Youn BS, Fukuda S, Kim YJ, Mantel C, Akashi M, Broxmeyer HE (June 2002). "C-kit associated with the transmembrane 4 superfamily proteins constitutes a functionally distinct subunit in human hematopoietic progenitors". Blood. 99 (12): 4413–21. doi:10.1182/blood.v99.12.4413. PMID12036870.
↑ 8.08.1Radford KJ, Thorne RF, Hersey P (May 1996). "CD63 associates with transmembrane 4 superfamily members, CD9 and CD81, and with beta 1 integrins in human melanoma". Biochem. Biophys. Res. Commun. 222 (1): 13–8. doi:10.1006/bbrc.1996.0690. PMID8630057.
↑Mazzocca A, Carloni V, Sciammetta S, Cordella C, Pantaleo P, Caldini A, Gentilini P, Pinzani M (September 2002). "Expression of transmembrane 4 superfamily (TM4SF) proteins and their role in hepatic stellate cell motility and wound healing migration". J. Hepatol. 37 (3): 322–30. doi:10.1016/s0168-8278(02)00175-7. PMID12175627.
↑Lozahic S, Christiansen D, Manié S, Gerlier D, Billard M, Boucheix C, Rubinstein E (March 2000). "CD46 (membrane cofactor protein) associates with multiple beta1 integrins and tetraspans". Eur. J. Immunol. 30 (3): 900–7. doi:10.1002/1521-4141(200003)30:3<900::AID-IMMU900>3.0.CO;2-X. PMID10741407.
↑Park KR, Inoue T, Ueda M, Hirano T, Higuchi T, Maeda M, Konishi I, Fujiwara H, Fujii S (March 2000). "CD9 is expressed on human endometrial epithelial cells in association with integrins alpha(6), alpha(3) and beta(1)". Mol. Hum. Reprod. 6 (3): 252–7. doi:10.1093/molehr/6.3.252. PMID10694273.
↑Hirano T, Higuchi T, Ueda M, Inoue T, Kataoka N, Maeda M, Fujiwara H, Fujii S (February 1999). "CD9 is expressed in extravillous trophoblasts in association with integrin alpha3 and integrin alpha5". Mol. Hum. Reprod. 5 (2): 162–7. doi:10.1093/molehr/5.2.162. PMID10065872.
↑Horváth G, Serru V, Clay D, Billard M, Boucheix C, Rubinstein E (November 1998). "CD19 is linked to the integrin-associated tetraspans CD9, CD81, and CD82". J. Biol. Chem. 273 (46): 30537–43. doi:10.1074/jbc.273.46.30537. PMID9804823.
↑Charrin S, Le Naour F, Oualid M, Billard M, Faure G, Hanash SM, Boucheix C, Rubinstein E (April 2001). "The major CD9 and CD81 molecular partner. Identification and characterization of the complexes". J. Biol. Chem. 276 (17): 14329–37. doi:10.1074/jbc.M011297200. PMID11278880.
↑Stipp CS, Orlicky D, Hemler ME (February 2001). "FPRP, a major, highly stoichiometric, highly specific CD81- and CD9-associated protein". J. Biol. Chem. 276 (7): 4853–62. doi:10.1074/jbc.M009859200. PMID11087758.
↑Tachibana I, Bodorova J, Berditchevski F, Zutter MM, Hemler ME (November 1997). "NAG-2, a novel transmembrane-4 superfamily (TM4SF) protein that complexes with integrins and other TM4SF proteins". J. Biol. Chem. 272 (46): 29181–9. doi:10.1074/jbc.272.46.29181. PMID9360996.
Horejsí V, Vlcek C (1991). "Novel structurally distinct family of leucocyte surface glycoproteins including CD9, CD37, CD53 and CD63". FEBS Lett. 288 (1–2): 1–4. doi:10.1016/0014-5793(91)80988-F. PMID1879540.
Berditchevski F (2002). "Complexes of tetraspanins with integrins: more than meets the eye". J. Cell Sci. 114 (Pt 23): 4143–51. PMID11739647.
Ninomiya H, Sims PJ (1992). "The human complement regulatory protein CD59 binds to the alpha-chain of C8 and to the "b"domain of C9". J. Biol. Chem. 267 (19): 13675–80. PMID1377690.
Boucheix C, Benoit P, Frachet P, Billard M, Worthington RE, Gagnon J, Uzan G (1991). "Molecular cloning of the CD9 antigen. A new family of cell surface proteins". J. Biol. Chem. 266 (1): 117–22. PMID1840589.
Iwamoto R, Senoh H, Okada Y, Uchida T, Mekada E (1991). "An antibody that inhibits the binding of diphtheria toxin to cells revealed the association of a 27-kDa membrane protein with the diphtheria toxin receptor". J. Biol. Chem. 266 (30): 20463–9. PMID1939101.
Benoit P, Gross MS, Frachet P, Frézal J, Uzan G, Boucheix C, Nguyen VC (1991). "Assignment of the human CD9 gene to chromosome 12 (region P13) by use of human specific DNA probes". Hum. Genet. 86 (3): 268–72. doi:10.1007/bf00202407. PMID1997380.
Lanza F, Wolf D, Fox CF, Kieffer N, Seyer JM, Fried VA, Coughlin SR, Phillips DR, Jennings LK (1991). "cDNA cloning and expression of platelet p24/CD9. Evidence for a new family of multiple membrane-spanning proteins". J. Biol. Chem. 266 (16): 10638–45. PMID2037603.
Higashihara M, Takahata K, Yatomi Y, Nakahara K, Kurokawa K (1990). "Purification and partial characterization of CD9 antigen of human platelets". FEBS Lett. 264 (2): 270–274. doi:10.1016/0014-5793(90)80265-K. PMID2358073.
Masellis-Smith A, Shaw AR (1994). "CD9-regulated adhesion. Anti-CD9 monoclonal antibody induce pre-B cell adhesion to bone marrow fibroblasts through de novo recognition of fibronectin". J. Immunol. 152 (6): 2768–77. PMID7511626.
Rubinstein E, Benoit P, Billard M, Plaisance S, Prenant M, Uzan G, Boucheix C (1993). "Organization of the human CD9 gene". Genomics. 16 (1): 132–138. doi:10.1006/geno.1993.1150. PMID8486348.
Radford KJ, Thorne RF, Hersey P (1996). "CD63 associates with transmembrane 4 superfamily members, CD9 and CD81, and with beta 1 integrins in human melanoma". Biochem. Biophys. Res. Commun. 222 (1): 13–18. doi:10.1006/bbrc.1996.0690. PMID8630057.
Schmidt C, Künemund V, Wintergerst ES, Schmitz B, Schachner M (1996). "CD9 of mouse brain is implicated in neurite outgrowth and cell migration in vitro and is associated with the alpha 6/beta 1 integrin and the neural adhesion molecule L1". J. Neurosci. Res. 43 (1): 12–31. doi:10.1002/jnr.490430103. PMID8838570.
Sincock PM, Mayrhofer G, Ashman LK (1997). "Localization of the transmembrane 4 superfamily (TM4SF) member PETA-3 (CD151) in normal human tissues: comparison with CD9, CD63, and alpha5beta1 integrin". J. Histochem. Cytochem. 45 (4): 515–25. doi:10.1177/002215549704500404. PMID9111230.
Rubinstein E, Poindessous-Jazat V, Le Naour F, Billard M, Boucheix C (1997). "CD9, but not other tetraspans, associates with the beta1 integrin precursor". Eur. J. Immunol. 27 (8): 1919–1927. doi:10.1002/eji.1830270815. PMID9295027.
Tachibana I, Bodorova J, Berditchevski F, Zutter MM, Hemler ME (1997). "NAG-2, a novel transmembrane-4 superfamily (TM4SF) protein that complexes with integrins and other TM4SF proteins". J. Biol. Chem. 272 (46): 29181–29189. doi:10.1074/jbc.272.46.29181. PMID9360996.