ID CD9_HUMAN Reviewed; 228 AA. AC P21926; D3DUQ9; Q5J7W6; Q96ES4; DT 01-MAY-1991, integrated into UniProtKB/Swiss-Prot. DT 23-JAN-2007, sequence version 4. DT 27-MAR-2024, entry version 219. DE RecName: Full=CD9 antigen {ECO:0000303|PubMed:1840589}; DE AltName: Full=5H9 antigen; DE AltName: Full=Cell growth-inhibiting gene 2 protein {ECO:0000303|Ref.6}; DE AltName: Full=Leukocyte antigen MIC3; DE AltName: Full=Motility-related protein {ECO:0000303|PubMed:8478605}; DE Short=MRP-1 {ECO:0000303|PubMed:8478605}; DE AltName: Full=Tetraspanin-29; DE Short=Tspan-29; DE AltName: Full=p24 {ECO:0000303|PubMed:2037603}; DE AltName: CD_antigen=CD9 {ECO:0000303|PubMed:1840589}; GN Name=CD9 {ECO:0000303|PubMed:1840589, ECO:0000312|HGNC:HGNC:1709}; GN Synonyms=MIC3, TSPAN29; ORFNames=GIG2 {ECO:0000303|Ref.6}; OS Homo sapiens (Human). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; OC Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; OC Homo. OX NCBI_TaxID=9606; RN [1] RP NUCLEOTIDE SEQUENCE [MRNA], AND PROTEIN SEQUENCE OF 2-5. RX PubMed=1840589; DOI=10.1016/s0021-9258(18)52410-8; RA Boucheix C., Benoit P., Frachet P., Billard M., Worthington R.E., RA Gagnon J., Uzan G.; RT "Molecular cloning of the CD9 antigen. A new family of cell surface RT proteins."; RL J. Biol. Chem. 266:117-122(1991). RN [2] RP NUCLEOTIDE SEQUENCE [MRNA], AND PARTIAL PROTEIN SEQUENCE. RX PubMed=2037603; DOI=10.1016/s0021-9258(18)99271-9; RA Lanza F., Wolf D., Fox C.F., Kieffer N., Seyer J.M., Fried V.A., RA Coughlin S.R., Phillips D.R., Jennings L.K.; RT "cDNA cloning and expression of platelet p24/CD9. Evidence for a new family RT of multiple membrane-spanning proteins."; RL J. Biol. Chem. 266:10638-10645(1991). RN [3] RP NUCLEOTIDE SEQUENCE [MRNA]. RX PubMed=1720807; DOI=10.1084/jem.174.6.1347; RA Miyake M., Koyama M., Seno M., Ikeyama S.; RT "Identification of the motility-related protein (MRP-1), recognized by RT monoclonal antibody M31-15, which inhibits cell motility."; RL J. Exp. Med. 174:1347-1354(1991). RN [4] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RC TISSUE=Leukocyte; RX PubMed=8486348; DOI=10.1006/geno.1993.1150; RA Rubinstein E., Benoit P., Billard M., Plaisance S., Prenant M., Uzan G., RA Boucheix C.; RT "Organization of the human CD9 gene."; RL Genomics 16:132-138(1993). RN [5] RP NUCLEOTIDE SEQUENCE [MRNA]. RX PubMed=15196249; DOI=10.1111/j.1365-2249.2004.02494.x; RA Kobayashi H., Hosono O., Iwata S., Kawasaki H., Kuwana M., Tanaka H., RA Dang N.H., Morimoto C.; RT "The tetraspanin CD9 is preferentially expressed on the human CD4(+)CD45RA+ RT naive T cell population and is involved in T cell activation."; RL Clin. Exp. Immunol. 137:101-108(2004). RN [6] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. RA Kim J.W.; RT "Identification of a human growth inhibition gene 2 (GIG2)."; RL Submitted (SEP-2003) to the EMBL/GenBank/DDBJ databases. RN [7] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RG SeattleSNPs variation discovery resource; RL Submitted (SEP-2003) to the EMBL/GenBank/DDBJ databases. RN [8] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RA Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., Mobarry C.M., RA Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., Flanigan M.J., RA Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., Hannenhalli S., RA Turner R., Yooseph S., Lu F., Nusskern D.R., Shue B.C., Zheng X.H., RA Zhong F., Delcher A.L., Huson D.H., Kravitz S.A., Mouchard L., Reinert K., RA Remington K.A., Clark A.G., Waterman M.S., Eichler E.E., Adams M.D., RA Hunkapiller M.W., Myers E.W., Venter J.C.; RL Submitted (SEP-2005) to the EMBL/GenBank/DDBJ databases. RN [9] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. RC TISSUE=Ovary; RX PubMed=15489334; DOI=10.1101/gr.2596504; RG The MGC Project Team; RT "The status, quality, and expansion of the NIH full-length cDNA project: RT the Mammalian Gene Collection (MGC)."; RL Genome Res. 14:2121-2127(2004). RN [10] RP PROTEIN SEQUENCE OF 2-21. RC TISSUE=Platelet; RX PubMed=2358073; DOI=10.1016/0014-5793(90)80265-k; RA Higashihara M., Takahata K., Yatomi Y., Nakahara K., Kurokawa K.; RT "Purification and partial characterization of CD9 antigen of human RT platelets."; RL FEBS Lett. 264:270-274(1990). RN [11] RP FUNCTION IN CELL MOTILITY AND METASTASIS. RX PubMed=8478605; DOI=10.1084/jem.177.5.1231; RA Ikeyama S., Koyama M., Yamaoko M., Sasada R., Miyake M.; RT "Suppression of cell motility and metastasis by transfection with human RT motility-related protein (MRP-1/CD9) DNA."; RL J. Exp. Med. 177:1231-1237(1993). RN [12] RP FUNCTION IN CELL ADHESION. RX PubMed=7511626; RA Masellis-Smith A., Shaw A.R.; RT "CD9-regulated adhesion. Anti-CD9 monoclonal antibody induce pre-B cell RT adhesion to bone marrow fibroblasts through de novo recognition of RT fibronectin."; RL J. Immunol. 152:2768-2777(1994). RN [13] RP FUNCTION IN SPERM-EGG FUSION. RX PubMed=14575715; DOI=10.1016/j.bbrc.2003.09.196; RA Higginbottom A., Takahashi Y., Bolling L., Coonrod S.A., White J.M., RA Partridge L.J., Monk P.N.; RT "Structural requirements for the inhibitory action of the CD9 large RT extracellular domain in sperm/oocyte binding and fusion."; RL Biochem. Biophys. Res. Commun. 311:208-214(2003). RN [14] RP FUNCTION, AND INTERACTION WITH CD81. RX PubMed=12796480; DOI=10.1083/jcb.200212031; RA Takeda Y., Tachibana I., Miyado K., Kobayashi M., Miyazaki T., RA Funakoshi T., Kimura H., Yamane H., Saito Y., Goto H., Yoneda T., RA Yoshida M., Kumagai T., Osaki T., Hayashi S., Kawase I., Mekada E.; RT "Tetraspanins CD9 and CD81 function to prevent the fusion of mononuclear RT phagocytes."; RL J. Cell Biol. 161:945-956(2003). RN [15] RP SUBUNIT. RX PubMed=14556650; DOI=10.1042/bj20031037; RA Kovalenko O.V., Yang X., Kolesnikova T.V., Hemler M.E.; RT "Evidence for specific tetraspanin homodimers: inhibition of palmitoylation RT makes cysteine residues available for cross-linking."; RL Biochem. J. 377:407-417(2004). RN [16] RP PALMITOYLATION AT CYS-9; CYS-78; CYS-79; CYS-87; CYS-218 AND CYS-219, AND RP MUTAGENESIS OF CYS-9; CYS-78; CYS-79; CYS-87; CYS-218 AND CYS-219. RX PubMed=11959120; DOI=10.1016/s0014-5793(02)02522-x; RA Charrin S., Manie S., Oualid M., Billard M., Boucheix C., Rubinstein E.; RT "Differential stability of tetraspanin/tetraspanin interactions: role of RT palmitoylation."; RL FEBS Lett. 516:139-144(2002). RN [17] RP INTERACTION WITH PTGFRN. RX PubMed=11278880; DOI=10.1074/jbc.m011297200; RA Charrin S., Le Naour F., Oualid M., Billard M., Faure G., Hanash S.M., RA Boucheix C., Rubinstein E.; RT "The major CD9 and CD81 molecular partner. Identification and RT characterization of the complexes."; RL J. Biol. Chem. 276:14329-14337(2001). RN [18] RP INTERACTION WITH IGSF8. RX PubMed=11504738; DOI=10.1074/jbc.m107338200; RA Stipp C.S., Kolesnikova T.V., Hemler M.E.; RT "EWI-2 is a major CD9 and CD81 partner and member of a novel Ig protein RT subfamily."; RL J. Biol. Chem. 276:40545-40554(2001). RN [19] RP FUNCTION, AND INTERACTION WITH PDPN. RX PubMed=18541721; DOI=10.1182/blood-2007-11-124693; RA Nakazawa Y., Sato S., Naito M., Kato Y., Mishima K., Arai H., Tsuruo T., RA Fujita N.; RT "Tetraspanin family member CD9 inhibits Aggrus/podoplanin-induced platelet RT aggregation and suppresses pulmonary metastasis."; RL Blood 112:1730-1739(2008). RN [20] RP PALMITOYLATION. RX PubMed=18508921; DOI=10.1091/mbc.e07-11-1164; RA Sharma C., Yang X.H., Hemler M.E.; RT "DHHC2 affects palmitoylation, stability, and functions of tetraspanins CD9 RT and CD151."; RL Mol. Biol. Cell 19:3415-3425(2008). RN [21] RP PALMITOYLATION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, INTERACTION WITH RP CD63, AND IDENTIFICATION IN A COMPLEX WITH ITGB3 AND CD63. RX PubMed=19640571; DOI=10.1016/j.thromres.2009.07.005; RA Israels S.J., McMillan-Ward E.M.; RT "Palmitoylation supports the association of tetraspanin CD63 with CD9 and RT integrin alphaIIbbeta3 in activated platelets."; RL Thromb. Res. 125:152-158(2010). RN [22] RP IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS]. RX PubMed=21269460; DOI=10.1186/1752-0509-5-17; RA Burkard T.R., Planyavsky M., Kaupe I., Breitwieser F.P., Buerckstuemmer T., RA Bennett K.L., Superti-Furga G., Colinge J.; RT "Initial characterization of the human central proteome."; RL BMC Syst. Biol. 5:17-17(2011). RN [23] RP INTERACTION WITH CD81. RX PubMed=23858057; DOI=10.1128/mcb.00302-13; RA Rocha-Perugini V., Zamai M., Gonzalez-Granado J.M., Barreiro O., Tejera E., RA Yanez-Mo M., Caiolfa V.R., Sanchez-Madrid F.; RT "CD81 controls sustained T cell activation signaling and defines the RT maturation stages of cognate immunological synapses."; RL Mol. Cell. Biol. 33:3644-3658(2013). RN [24] RP DISULFIDE BONDS. RX PubMed=25551757; DOI=10.1371/journal.pone.0116289; RA Hulme R.S., Higginbottom A., Palmer J., Partridge L.J., Monk P.N.; RT "Distinct regions of the large extracellular domain of tetraspanin CD9 are RT involved in the control of human multinucleated giant cell formation."; RL PLoS ONE 9:E116289-E116289(2014). RN [25] RP INTERACTION WITH INTEGRIN ITGAV:ITGB3. RX PubMed=27993971; DOI=10.1042/bcj20160998; RA Yu J., Lee C.Y., Changou C.A., Cedano-Prieto D.M., Takada Y.K., Takada Y.; RT "The CD9, CD81, and CD151 EC2 domains bind to the classical RGD-binding RT site of integrin alphavbeta3."; RL Biochem. J. 474:589-596(2017). CC -!- FUNCTION: Integral membrane protein associated with integrins, which CC regulates different processes, such as sperm-egg fusion, platelet CC activation and aggregation, and cell adhesion (PubMed:8478605, CC PubMed:14575715, PubMed:18541721). Present at the cell surface of CC oocytes and plays a key role in sperm-egg fusion, possibly by CC organizing multiprotein complexes and the morphology of the membrane CC required for the fusion (By similarity). In myoblasts, associates with CC CD81 and PTGFRN and inhibits myotube fusion during muscle regeneration CC (By similarity). In macrophages, associates with CD81 and beta-1 and CC beta-2 integrins, and prevents macrophage fusion into multinucleated CC giant cells specialized in ingesting complement-opsonized large CC particles (PubMed:12796480). Also prevents the fusion between CC mononuclear cell progenitors into osteoclasts in charge of bone CC resorption (By similarity). Acts as a receptor for PSG17 (By CC similarity). Involved in platelet activation and aggregation CC (PubMed:18541721). Regulates paranodal junction formation (By CC similarity). Involved in cell adhesion, cell motility and tumor CC metastasis (PubMed:8478605, PubMed:7511626). CC {ECO:0000250|UniProtKB:P40240, ECO:0000269|PubMed:12796480, CC ECO:0000269|PubMed:14575715, ECO:0000269|PubMed:18541721, CC ECO:0000269|PubMed:7511626, ECO:0000269|PubMed:8478605}. CC -!- SUBUNIT: Forms both disulfide-linked homodimers and higher CC homooligomers as well as heterooligomers with other members of the CC tetraspanin family (PubMed:14556650). Interacts (via the second CC extracellular domain) with integrin ITGAV:ITGB3 (PubMed:19640571, CC PubMed:27993971). Interacts with integrin ITGA6:ITGB1; interaction CC takes place in oocytes and is involved in sperm-egg fusion (By CC similarity). Part of integrin-tetraspanin complexes composed of CD81, CC beta-1 and beta-2 integrins in the membrane of monocyte/macrophages CC (PubMed:12796480). Interacts with CD63; identified in a complex with CC CD63 and ITGB3 (PubMed:19640571). Associates with CR2/CD21 and with CC PTGFRN/CD9P1 (PubMed:11278880). Part of a complex composed of CD9, CC CD81, PTGFRN and IGSF8 (By similarity). Interacts directly with IGSF8 CC (PubMed:11504738). Interacts with PDPN; this interaction is homophilic CC and attenuates platelet aggregation and pulmonary metastasis induced by CC PDPN (PubMed:18541721). Interacts (on T cell side) with CD81 at CC immunological synapses between antigen-presenting cells and T cells CC (PubMed:23858057). {ECO:0000250|UniProtKB:P40240, CC ECO:0000269|PubMed:11278880, ECO:0000269|PubMed:11504738, CC ECO:0000269|PubMed:12796480, ECO:0000269|PubMed:14556650, CC ECO:0000269|PubMed:18541721, ECO:0000269|PubMed:19640571, CC ECO:0000269|PubMed:23858057, ECO:0000269|PubMed:27993971}. CC -!- INTERACTION: CC P21926; O14672: ADAM10; NbExp=17; IntAct=EBI-4280101, EBI-1536151; CC P21926; P08473: MME; NbExp=6; IntAct=EBI-4280101, EBI-353759; CC P21926; Q2M2E3: ODF4; NbExp=3; IntAct=EBI-4280101, EBI-12382569; CC P21926; Q9P2B2: PTGFRN; NbExp=10; IntAct=EBI-4280101, EBI-4290465; CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000269|PubMed:19640571}; CC Multi-pass membrane protein {ECO:0000269|PubMed:19640571}. Membrane CC {ECO:0000269|PubMed:19640571}; Multi-pass membrane protein CC {ECO:0000269|PubMed:19640571}. Secreted, extracellular exosome CC {ECO:0000250|UniProtKB:P40240}. Note=Present at the cell surface of CC oocytes. Accumulates in the adhesion area between the sperm and egg CC following interaction between IZUMO1 and its receptor IZUMO1R/JUNO. CC {ECO:0000250|UniProtKB:P40240}. CC -!- TISSUE SPECIFICITY: Detected in platelets (at protein level) CC (PubMed:19640571). Expressed by a variety of hematopoietic and CC epithelial cells (PubMed:19640571). {ECO:0000269|PubMed:19640571}. CC -!- PTM: Palmitoylated at a low, basal level in unstimulated platelets. The CC level of palmitoylation increases when platelets are activated by CC thrombin (in vitro). The protein exists in three forms with molecular CC masses between 22 and 27 kDa, and is known to carry covalently linked CC fatty acids (PubMed:11959120). Palmitoylation by ZDHHC2 regulates CD9 CC expression, association with other tetraspanin family proteins and CC function in cell adhesion (PubMed:18508921). CC {ECO:0000269|PubMed:11959120, ECO:0000269|PubMed:18508921}. CC -!- SIMILARITY: Belongs to the tetraspanin (TM4SF) family. {ECO:0000305}. CC -!- WEB RESOURCE: Name=SeattleSNPs; CC URL="http://pga.gs.washington.edu/data/cd9/"; CC -!- WEB RESOURCE: Name=Atlas of Genetics and Cytogenetics in Oncology and CC Haematology; CC URL="https://atlasgeneticsoncology.org/gene/995/CD9"; CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; M38690; AAA80320.1; -; mRNA. DR EMBL; L34068; AAA59982.1; -; mRNA. DR EMBL; X60111; CAA42708.1; -; mRNA. DR EMBL; S60489; AAC60586.1; -; Genomic_DNA. DR EMBL; S60462; AAC60586.1; JOINED; Genomic_DNA. DR EMBL; S60463; AAC60586.1; JOINED; Genomic_DNA. DR EMBL; S60464; AAC60586.1; JOINED; Genomic_DNA. DR EMBL; S60700; AAC60586.1; JOINED; Genomic_DNA. DR EMBL; S60699; AAC60586.1; JOINED; Genomic_DNA. DR EMBL; S60465; AAC60586.1; JOINED; Genomic_DNA. DR EMBL; S60472; AAC60586.1; JOINED; Genomic_DNA. DR EMBL; L08118; -; NOT_ANNOTATED_CDS; Genomic_DNA. DR EMBL; L08119; AAA51954.1; ALT_SEQ; Genomic_DNA. DR EMBL; L08120; AAA51955.1; ALT_SEQ; Genomic_DNA. DR EMBL; L08121; AAA51956.1; -; Genomic_DNA. DR EMBL; L08122; AAA51957.1; -; Genomic_DNA. DR EMBL; L08123; AAA51958.1; -; Genomic_DNA. DR EMBL; L08124; AAA51959.1; -; Genomic_DNA. DR EMBL; L08125; -; NOT_ANNOTATED_CDS; Genomic_DNA. DR EMBL; AB079244; BAE71132.1; -; mRNA. DR EMBL; AY423720; AAS00483.1; -; mRNA. DR EMBL; AY422198; AAQ87878.1; -; Genomic_DNA. DR EMBL; CH471116; EAW88812.1; -; Genomic_DNA. DR EMBL; CH471116; EAW88813.1; -; Genomic_DNA. DR EMBL; BC011988; AAH11988.1; -; mRNA. DR CCDS; CCDS8540.1; -. DR PIR; A46123; A40402. DR RefSeq; NP_001317241.1; NM_001330312.1. DR RefSeq; NP_001760.1; NM_001769.3. DR PDB; 6K4J; X-ray; 2.70 A; A=1-228. DR PDB; 6RLO; X-ray; 2.20 A; I/J/K/L=114-191. DR PDB; 6RLR; X-ray; 2.00 A; A/B/C/D=114-191. DR PDB; 6Z1V; X-ray; 1.33 A; A=114-191. DR PDB; 6Z20; X-ray; 2.68 A; A/C=114-191. DR PDBsum; 6K4J; -. DR PDBsum; 6RLO; -. DR PDBsum; 6RLR; -. DR PDBsum; 6Z1V; -. DR PDBsum; 6Z20; -. DR AlphaFoldDB; P21926; -. DR SMR; P21926; -. DR BioGRID; 107366; 81. DR CORUM; P21926; -. DR DIP; DIP-1122N; -. DR IntAct; P21926; 90. DR MINT; P21926; -. DR STRING; 9606.ENSP00000371958; -. DR DrugBank; DB05398; C31G. DR TCDB; 8.A.40.1.9; the tetraspanin (tetraspanin) family. DR GlyCosmos; P21926; 2 sites, No reported glycans. DR GlyGen; P21926; 4 sites, 1 O-linked glycan (1 site). DR iPTMnet; P21926; -. DR PhosphoSitePlus; P21926; -. DR SwissPalm; P21926; -. DR BioMuta; CD9; -. DR DMDM; 231724; -. DR EPD; P21926; -. DR jPOST; P21926; -. DR MassIVE; P21926; -. DR MaxQB; P21926; -. DR PaxDb; 9606-ENSP00000371958; -. DR PeptideAtlas; P21926; -. DR PRIDE; P21926; -. DR ProteomicsDB; 53942; -. DR Pumba; P21926; -. DR Antibodypedia; 3733; 2013 antibodies from 49 providers. DR DNASU; 928; -. DR Ensembl; ENST00000009180.10; ENSP00000009180.4; ENSG00000010278.15. DR Ensembl; ENST00000382518.6; ENSP00000371958.1; ENSG00000010278.15. DR Ensembl; ENST00000538834.6; ENSP00000496639.1; ENSG00000010278.15. DR GeneID; 928; -. DR KEGG; hsa:928; -. DR MANE-Select; ENST00000009180.10; ENSP00000009180.4; NM_001769.4; NP_001760.1. DR UCSC; uc001qnq.3; human. DR AGR; HGNC:1709; -. DR CTD; 928; -. DR DisGeNET; 928; -. DR GeneCards; CD9; -. DR HGNC; HGNC:1709; CD9. DR HPA; ENSG00000010278; Low tissue specificity. DR MIM; 143030; gene. DR neXtProt; NX_P21926; -. DR OpenTargets; ENSG00000010278; -. DR PharmGKB; PA26247; -. DR VEuPathDB; HostDB:ENSG00000010278; -. DR eggNOG; KOG3882; Eukaryota. DR GeneTree; ENSGT00940000155083; -. DR HOGENOM; CLU_055524_10_1_1; -. DR InParanoid; P21926; -. DR OMA; EQENNHS; -. DR OrthoDB; 2964111at2759; -. DR PhylomeDB; P21926; -. DR TreeFam; TF352895; -. DR PathwayCommons; P21926; -. DR Reactome; R-HSA-114608; Platelet degranulation. DR Reactome; R-HSA-1300645; Acrosome Reaction and Sperm:Oocyte Membrane Binding. DR Reactome; R-HSA-5336415; Uptake and function of diphtheria toxin. DR SignaLink; P21926; -. DR BioGRID-ORCS; 928; 40 hits in 1154 CRISPR screens. DR ChiTaRS; CD9; human. DR GeneWiki; CD9; -. DR GenomeRNAi; 928; -. DR Pharos; P21926; Tbio. DR PRO; PR:P21926; -. DR Proteomes; UP000005640; Chromosome 12. DR RNAct; P21926; Protein. DR Bgee; ENSG00000010278; Expressed in pharyngeal mucosa and 204 other cell types or tissues. DR ExpressionAtlas; P21926; baseline and differential. DR GO; GO:0030669; C:clathrin-coated endocytic vesicle membrane; TAS:Reactome. DR GO; GO:0030666; C:endocytic vesicle membrane; TAS:Reactome. DR GO; GO:0009897; C:external side of plasma membrane; IEA:Ensembl. DR GO; GO:0070062; C:extracellular exosome; IDA:UniProtKB. DR GO; GO:0005615; C:extracellular space; HDA:UniProtKB. DR GO; GO:1903561; C:extracellular vesicle; HDA:UniProtKB. DR GO; GO:0005925; C:focal adhesion; HDA:UniProtKB. DR GO; GO:0016020; C:membrane; ISS:UniProtKB. DR GO; GO:0005886; C:plasma membrane; ISS:UniProtKB. DR GO; GO:0031092; C:platelet alpha granule membrane; TAS:Reactome. DR GO; GO:0032991; C:protein-containing complex; IDA:ARUK-UCL. DR GO; GO:0005178; F:integrin binding; IDA:UniProtKB. DR GO; GO:0007155; P:cell adhesion; IDA:UniProtKB. DR GO; GO:0008283; P:cell population proliferation; IEA:Ensembl. DR GO; GO:0071404; P:cellular response to low-density lipoprotein particle stimulus; ISS:UniProtKB. DR GO; GO:0007342; P:fusion of sperm to egg plasma membrane involved in single fertilization; IDA:UniProtKB. DR GO; GO:0008347; P:glial cell migration; IMP:FlyBase. DR GO; GO:0014905; P:myoblast fusion involved in skeletal muscle regeneration; ISS:UniProtKB. DR GO; GO:0008285; P:negative regulation of cell population proliferation; IEA:Ensembl. DR GO; GO:0090331; P:negative regulation of platelet aggregation; IDA:UniProtKB. DR GO; GO:0030913; P:paranodal junction assembly; ISS:UniProtKB. DR GO; GO:0030168; P:platelet activation; NAS:UniProtKB. DR GO; GO:0031623; P:receptor internalization; ISS:UniProtKB. DR GO; GO:1905521; P:regulation of macrophage migration; IEA:Ensembl. DR GO; GO:0035036; P:sperm-egg recognition; ISS:UniProtKB. DR CDD; cd03152; CD9_LEL; 1. DR Gene3D; 1.10.1450.10; Tetraspanin; 1. DR InterPro; IPR042055; CD9_LEL. DR InterPro; IPR018499; Tetraspanin/Peripherin. DR InterPro; IPR000301; Tetraspanin_animals. DR InterPro; IPR018503; Tetraspanin_CS. DR InterPro; IPR008952; Tetraspanin_EC2_sf. DR PANTHER; PTHR19282:SF163; CD9 ANTIGEN; 1. DR PANTHER; PTHR19282; TETRASPANIN; 1. DR Pfam; PF00335; Tetraspanin; 1. DR PIRSF; PIRSF002419; Tetraspanin; 1. DR PRINTS; PR00259; TMFOUR. DR SUPFAM; SSF48652; Tetraspanin; 1. DR PROSITE; PS00421; TM4_1; 1. DR Genevisible; P21926; HS. PE 1: Evidence at protein level; KW 3D-structure; Cell adhesion; Cell membrane; Direct protein sequencing; KW Disulfide bond; Fertilization; Glycoprotein; Lipoprotein; Membrane; KW Palmitate; Reference proteome; Secreted; Transmembrane; KW Transmembrane helix. FT INIT_MET 1 FT /note="Removed" FT /evidence="ECO:0000269|PubMed:1840589, FT ECO:0000269|PubMed:2358073" FT CHAIN 2..228 FT /note="CD9 antigen" FT /id="PRO_0000219205" FT TOPO_DOM 2..12 FT /note="Cytoplasmic" FT /evidence="ECO:0000255" FT TRANSMEM 13..33 FT /note="Helical" FT /evidence="ECO:0000255" FT TOPO_DOM 34..55 FT /note="Extracellular" FT /evidence="ECO:0000255" FT TRANSMEM 56..76 FT /note="Helical" FT /evidence="ECO:0000255" FT TOPO_DOM 77..87 FT /note="Cytoplasmic" FT /evidence="ECO:0000255" FT TRANSMEM 88..111 FT /note="Helical" FT /evidence="ECO:0000255" FT TOPO_DOM 112..195 FT /note="Extracellular" FT /evidence="ECO:0000255" FT TRANSMEM 196..221 FT /note="Helical" FT /evidence="ECO:0000255" FT TOPO_DOM 222..228 FT /note="Cytoplasmic" FT /evidence="ECO:0000255" FT LIPID 9 FT /note="S-palmitoyl cysteine" FT /evidence="ECO:0000305|PubMed:11959120" FT LIPID 78 FT /note="S-palmitoyl cysteine" FT /evidence="ECO:0000305|PubMed:11959120" FT LIPID 79 FT /note="S-palmitoyl cysteine" FT /evidence="ECO:0000305|PubMed:11959120" FT LIPID 87 FT /note="S-palmitoyl cysteine" FT /evidence="ECO:0000305|PubMed:11959120" FT LIPID 218 FT /note="S-palmitoyl cysteine" FT /evidence="ECO:0000305|PubMed:11959120" FT LIPID 219 FT /note="S-palmitoyl cysteine" FT /evidence="ECO:0000305|PubMed:11959120" FT CARBOHYD 52 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255" FT CARBOHYD 53 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255" FT DISULFID 152..181 FT /evidence="ECO:0000269|PubMed:25551757" FT DISULFID 153..167 FT /evidence="ECO:0000269|PubMed:25551757" FT MUTAGEN 9 FT /note="C->A: Loss of palmitoylation; when associated with FT A-78; A-79; A-87; A-218 and A-219." FT /evidence="ECO:0000269|PubMed:11959120" FT MUTAGEN 78 FT /note="C->A: Loss of palmitoylation; when associated with FT A-9; A-79; A-87; A-218 and A-219." FT /evidence="ECO:0000269|PubMed:11959120" FT MUTAGEN 79 FT /note="C->A: Loss of palmitoylation; when associated with FT A-9; A-78; A-87; A-218 and A-219." FT /evidence="ECO:0000269|PubMed:11959120" FT MUTAGEN 87 FT /note="C->A: Loss of palmitoylation; when associated with FT A-9; A-78; A-79; A-218 and A-219." FT /evidence="ECO:0000269|PubMed:11959120" FT MUTAGEN 218 FT /note="C->A: Loss of palmitoylation; when associated with FT A-9; A-78; A-79; A-87 and A-219." FT /evidence="ECO:0000269|PubMed:11959120" FT MUTAGEN 219 FT /note="C->A: Loss of palmitoylation; when associated with FT A-9; A-78; A-79; A-87 and A-218." FT /evidence="ECO:0000269|PubMed:11959120" FT CONFLICT 215 FT /note="M -> T (in Ref. 9; AAH11988)" FT /evidence="ECO:0000305" FT HELIX 5..37 FT /evidence="ECO:0007829|PDB:6K4J" FT HELIX 41..45 FT /evidence="ECO:0007829|PDB:6K4J" FT HELIX 55..82 FT /evidence="ECO:0007829|PDB:6K4J" FT HELIX 86..111 FT /evidence="ECO:0007829|PDB:6K4J" FT HELIX 114..133 FT /evidence="ECO:0007829|PDB:6Z1V" FT HELIX 137..139 FT /evidence="ECO:0007829|PDB:6Z1V" FT HELIX 140..150 FT /evidence="ECO:0007829|PDB:6Z1V" FT TURN 154..156 FT /evidence="ECO:0007829|PDB:6K4J" FT HELIX 161..166 FT /evidence="ECO:0007829|PDB:6Z1V" FT TURN 169..172 FT /evidence="ECO:0007829|PDB:6Z1V" FT HELIX 173..175 FT /evidence="ECO:0007829|PDB:6Z1V" FT HELIX 181..190 FT /evidence="ECO:0007829|PDB:6Z1V" FT HELIX 193..222 FT /evidence="ECO:0007829|PDB:6K4J" SQ SEQUENCE 228 AA; 25416 MW; F68333E0C20611D8 CRC64; MPVKGGTKCI KYLLFGFNFI FWLAGIAVLA IGLWLRFDSQ TKSIFEQETN NNNSSFYTGV YILIGAGALM MLVGFLGCCG AVQESQCMLG LFFGFLLVIF AIEIAAAIWG YSHKDEVIKE VQEFYKDTYN KLKTKDEPQR ETLKAIHYAL NCCGLAGGVE QFISDICPKK DVLETFTVKS CPDAIKEVFD NKFHIIGAVG IGIAVVMIFG MIFSMILCCA IRRNREMV //