ID CD8A_HUMAN Reviewed; 235 AA. AC P01732; B4DT80; D6W5M8; Q13970; Q4ZG17; DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot. DT 21-JUL-1986, sequence version 1. DT 13-FEB-2019, entry version 201. DE RecName: Full=T-cell surface glycoprotein CD8 alpha chain; DE AltName: Full=T-lymphocyte differentiation antigen T8/Leu-2; DE AltName: CD_antigen=CD8a; DE Flags: Precursor; GN Name=CD8A; Synonyms=MAL; OS Homo sapiens (Human). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; OC Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; OC Catarrhini; Hominidae; Homo. OX NCBI_TaxID=9606; RN [1] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). RX PubMed=3871356; DOI=10.1016/0092-8674(85)90138-2; RA Littman D.R., Thomas Y., Maddon P.J., Chess L., Axel R.; RT "The isolation and sequence of the gene encoding T8: a molecule RT defining functional classes of T lymphocytes."; RL Cell 40:237-246(1985). RN [2] RP NUCLEOTIDE SEQUENCE (ISOFORM 1). RX PubMed=3936473; RA Parnes J.R., Sizer K.C., Sukhatme V.P., Hunkapiller T.; RT "Structure of Leu-2/T8 as deduced from the sequence of a cDNA clone."; RL Behring Inst. Mitt. 77:48-55(1985). RN [3] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). RX PubMed=3918796; DOI=10.1016/0092-8674(85)90207-7; RA Sukhatme V.P., Sizer K.C., Vollmer A.C., Hunkapiller T., Parnes J.R.; RT "The T cell differentiation antigen Leu-2/T8 is homologous to RT immunoglobulin and T cell receptor variable regions."; RL Cell 40:591-597(1985). RN [4] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=2509342; DOI=10.1007/BF02425282; RA Nakayama K., Tokito S., Okumura K., Nakauchi H.; RT "Structure and expression of the gene encoding CD8 alpha chain (Leu- RT 2/T8)."; RL Immunogenetics 30:393-397(1989). RN [5] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORM 2), AND ALTERNATIVE RP SPLICING. RX PubMed=2496167; RA Norment A.M., Lonberg N., Lacy E., Littman D.R.; RT "Alternatively spliced mRNA encodes a secreted form of human CD8 RT alpha. Characterization of the human CD8 alpha gene."; RL J. Immunol. 142:3312-3319(1989). RN [6] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 3). RC TISSUE=Pericardium; RX PubMed=14702039; DOI=10.1038/ng1285; RA Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., RA Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., RA Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S., RA Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., RA Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., RA Sudo H., Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., RA Takahashi M., Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., RA Abe K., Kamihara K., Katsuta N., Sato K., Tanikawa M., Yamazaki M., RA Ninomiya K., Ishibashi T., Yamashita H., Murakawa K., Fujimori K., RA Tanai H., Kimata M., Watanabe M., Hiraoka S., Chiba Y., Ishida S., RA Ono Y., Takiguchi S., Watanabe S., Yosida M., Hotuta T., Kusano J., RA Kanehori K., Takahashi-Fujii A., Hara H., Tanase T.-O., Nomura Y., RA Togiya S., Komai F., Hara R., Takeuchi K., Arita M., Imose N., RA Musashino K., Yuuki H., Oshima A., Sasaki N., Aotsuka S., RA Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., RA Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., RA Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., RA Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., RA Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., RA Fujimori Y., Komiyama M., Tashiro H., Tanigami A., Fujiwara T., RA Ono T., Yamada K., Fujii Y., Ozaki K., Hirao M., Ohmori Y., RA Kawabata A., Hikiji T., Kobatake N., Inagaki H., Ikema Y., Okamoto S., RA Okitani R., Kawakami T., Noguchi S., Itoh T., Shigeta K., Senba T., RA Matsumura K., Nakajima Y., Mizuno T., Morinaga M., Sasaki M., RA Togashi T., Oyama M., Hata H., Watanabe M., Komatsu T., RA Mizushima-Sugano J., Satoh T., Shirai Y., Takahashi Y., Nakagawa K., RA Okumura K., Nagase T., Nomura N., Kikuchi H., Masuho Y., Yamashita R., RA Nakai K., Yada T., Nakamura Y., Ohara O., Isogai T., Sugano S.; RT "Complete sequencing and characterization of 21,243 full-length human RT cDNAs."; RL Nat. Genet. 36:40-45(2004). RN [7] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RX PubMed=15815621; DOI=10.1038/nature03466; RA Hillier L.W., Graves T.A., Fulton R.S., Fulton L.A., Pepin K.H., RA Minx P., Wagner-McPherson C., Layman D., Wylie K., Sekhon M., RA Becker M.C., Fewell G.A., Delehaunty K.D., Miner T.L., Nash W.E., RA Kremitzki C., Oddy L., Du H., Sun H., Bradshaw-Cordum H., Ali J., RA Carter J., Cordes M., Harris A., Isak A., van Brunt A., Nguyen C., RA Du F., Courtney L., Kalicki J., Ozersky P., Abbott S., Armstrong J., RA Belter E.A., Caruso L., Cedroni M., Cotton M., Davidson T., Desai A., RA Elliott G., Erb T., Fronick C., Gaige T., Haakenson W., Haglund K., RA Holmes A., Harkins R., Kim K., Kruchowski S.S., Strong C.M., RA Grewal N., Goyea E., Hou S., Levy A., Martinka S., Mead K., RA McLellan M.D., Meyer R., Randall-Maher J., Tomlinson C., RA Dauphin-Kohlberg S., Kozlowicz-Reilly A., Shah N., RA Swearengen-Shahid S., Snider J., Strong J.T., Thompson J., Yoakum M., RA Leonard S., Pearman C., Trani L., Radionenko M., Waligorski J.E., RA Wang C., Rock S.M., Tin-Wollam A.-M., Maupin R., Latreille P., RA Wendl M.C., Yang S.-P., Pohl C., Wallis J.W., Spieth J., Bieri T.A., RA Berkowicz N., Nelson J.O., Osborne J., Ding L., Meyer R., Sabo A., RA Shotland Y., Sinha P., Wohldmann P.E., Cook L.L., Hickenbotham M.T., RA Eldred J., Williams D., Jones T.A., She X., Ciccarelli F.D., RA Izaurralde E., Taylor J., Schmutz J., Myers R.M., Cox D.R., Huang X., RA McPherson J.D., Mardis E.R., Clifton S.W., Warren W.C., RA Chinwalla A.T., Eddy S.R., Marra M.A., Ovcharenko I., Furey T.S., RA Miller W., Eichler E.E., Bork P., Suyama M., Torrents D., RA Waterston R.H., Wilson R.K.; RT "Generation and annotation of the DNA sequences of human chromosomes 2 RT and 4."; RL Nature 434:724-731(2005). RN [8] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RA Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., RA Mobarry C.M., Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., RA Flanigan M.J., Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., RA Hannenhalli S., Turner R., Yooseph S., Lu F., Nusskern D.R., RA Shue B.C., Zheng X.H., Zhong F., Delcher A.L., Huson D.H., RA Kravitz S.A., Mouchard L., Reinert K., Remington K.A., Clark A.G., RA Waterman M.S., Eichler E.E., Adams M.D., Hunkapiller M.W., Myers E.W., RA Venter J.C.; RL Submitted (SEP-2005) to the EMBL/GenBank/DDBJ databases. RN [9] RP NUCLEOTIDE SEQUENCE OF 168-235 (ISOFORMS 1 AND 2). RX PubMed=2536941; DOI=10.1073/pnas.86.3.998; RA Giblin P., Ledbetter J.A., Kavathas P.; RT "A secreted form of the human lymphocyte cell surface molecule CD8 RT arises from alternative splicing."; RL Proc. Natl. Acad. Sci. U.S.A. 86:998-1002(1989). RN [10] RP SUBUNIT. RX PubMed=6605969; RA Snow P.M., Terhorst C.; RT "The T8 antigen is a multimeric complex of two distinct subunits on RT human thymocytes but consists of homomultimeric forms on peripheral RT blood T lymphocytes."; RL J. Biol. Chem. 258:14675-14681(1983). RN [11] RP PHOSPHORYLATION. RX PubMed=2512251; RA DiSanto J.P., Klein J.S., Flomenberg N.; RT "Phosphorylation and down-regulation of CD4 and CD8 in human CTLs and RT mouse L cells."; RL Immunogenetics 30:494-501(1989). RN [12] RP GLYCOSYLATION, AND SUBCELLULAR LOCATION. RX PubMed=1460019; RA Pascale M.C., Erra M.C., Malagolini N., Serafini-Cessi F., Leone A., RA Bonatti S.; RT "Post-translational processing of an O-glycosylated protein, the human RT CD8 glycoprotein, during the intracellular transport to the plasma RT membrane."; RL J. Biol. Chem. 267:25196-25201(1992). RN [13] RP SUBCELLULAR LOCATION. RX PubMed=7923932; RA Schlesinger M., Chu F.N., Badamchian M., Jiang J.D., Roboz J.P., RA Goldstein A.L., Bekesi J.G.; RT "A distinctive form of soluble CD8 is secreted by stimulated CD8+ RT cells in HIV-1-infected and high-risk individuals."; RL Clin. Immunol. Immunopathol. 73:252-260(1994). RN [14] RP SUBUNIT, AND INTERACTION WITH HLA-G. RX PubMed=12853576; DOI=10.1073/pnas.1431057100; RA Shiroishi M., Tsumoto K., Amano K., Shirakihara Y., Colonna M., RA Braud V.M., Allan D.S.J., Makadzange A., Rowland-Jones S., RA Willcox B.E., Jones E.Y., van der Merwe P.A., Kumagai I., Maenaka K.; RT "Human inhibitory receptors Ig-like transcript 2 (ILT2) and ILT4 RT compete with CD8 for MHC class I binding and bind preferentially to RT HLA-G."; RL Proc. Natl. Acad. Sci. U.S.A. 100:8856-8861(2003). RN [15] RP FUNCTION, AND TISSUE SPECIFICITY. RX PubMed=16236125; DOI=10.1111/j.1365-2567.2005.02235.x; RA Addison E.G., North J., Bakhsh I., Marden C., Haq S., Al-Sarraj S., RA Malayeri R., Wickremasinghe R.G., Davies J.K., Lowdell M.W.; RT "Ligation of CD8alpha on human natural killer cells prevents RT activation-induced apoptosis and enhances cytolytic activity."; RL Immunology 116:354-361(2005). RN [16] RP FUNCTION, TISSUE SPECIFICITY, AND SUBCELLULAR LOCATION. RX PubMed=17678538; DOI=10.1186/1471-2172-8-12; RA Gibbings D.J., Marcet-Palacios M., Sekar Y., Ng M.C., Befus A.D.; RT "CD8 alpha is expressed by human monocytes and enhances Fc gamma R- RT dependent responses."; RL BMC Immunol. 8:12-12(2007). RN [17] RP SUBCELLULAR LOCATION, PALMITOYLATION AT CYS-206, AND MUTAGENESIS OF RP CYS-206. RX PubMed=17341584; DOI=10.1074/jbc.M701027200; RA Pang D.J., Hayday A.C., Bijlmakers M.J.; RT "CD8 Raft localization is induced by its assembly into CD8alpha beta RT heterodimers, Not CD8alpha alpha homodimers."; RL J. Biol. Chem. 282:13884-13894(2007). RN [18] RP FUNCTION. RX PubMed=23657257; DOI=10.1038/nature12110; RA Zhu J., Peng T., Johnston C., Phasouk K., Kask A.S., Klock A., Jin L., RA Diem K., Koelle D.M., Wald A., Robins H., Corey L.; RT "Immune surveillance by CD8alphaalpha+ skin-resident T cells in human RT herpes virus infection."; RL Nature 497:494-497(2013). RN [19] RP FUNCTION, AND TISSUE SPECIFICITY. RX PubMed=26082771; DOI=10.3389/fmicb.2015.00557; RA Schuster P., Thomann S., Werner M., Vollmer J., Schmidt B.; RT "A subset of human plasmacytoid dendritic cells expresses CD8alpha RT upon exposure to herpes simplex virus type 1."; RL Front. Microbiol. 6:557-557(2015). RN [20] RP X-RAY CRYSTALLOGRAPHY (2.60 ANGSTROMS) OF 22-135, AND DISULFIDE BOND. RX PubMed=1547508; DOI=10.1016/0092-8674(92)90085-Q; RA Leahy D.J., Axel R., Hendrickson W.A.; RT "Crystal structure of a soluble form of the human T cell coreceptor RT CD8 at 2.6-A resolution."; RL Cell 68:1145-1162(1992). RN [21] RP X-RAY CRYSTALLOGRAPHY (2.65 ANGSTROMS) OF 22-141 IN COMPLEX WITH RP HLA-A/B2M DIMER, AND DISULFIDE BOND. RX PubMed=9177355; DOI=10.1038/42523; RA Gao G.F., Tormo J., Gerth U.C., Wyer J.R., McMichael A.J., RA Stuart D.I., Bell J.I., Jones E.Y., Jakobsen B.K.; RT "Crystal structure of the complex between human CD8alpha(alpha) and RT HLA-A2."; RL Nature 387:630-634(1997). RN [22] RP STRUCTURE BY NMR OF 209-227 IN COMPLEX WITH LCK. RX PubMed=14500983; DOI=10.1126/science.1085643; RA Kim P.W., Sun Z.Y., Blacklow S.C., Wagner G., Eck M.J.; RT "A zinc clasp structure tethers Lck to T cell coreceptors CD4 and RT CD8."; RL Science 301:1725-1728(2003). RN [23] RP VARIANT CD8 DEFICIENCY SER-111, AND MUTAGENESIS OF GLY-111. RX PubMed=11435463; DOI=10.1172/JCI10993; RA de la Calle-Martin O., Hernandez M., Ordi J., Casamitjana N., RA Arostegui J.I., Caragol I., Ferrando M., Labrador M., RA Rodriguez-Sanchez J.L., Espanol T.; RT "Familial CD8 deficiency due to a mutation in the CD8 alpha gene."; RL J. Clin. Invest. 108:117-123(2001). CC -!- FUNCTION: Integral membrane glycoprotein that plays an essential CC role in the immune response and serves multiple functions in CC responses against both external and internal offenses. In T-cells, CC functions primarily as a coreceptor for MHC class I CC molecule:peptide complex. The antigens presented by class I CC peptides are derived from cytosolic proteins while class II CC derived from extracellular proteins. Interacts simultaneously with CC the T-cell receptor (TCR) and the MHC class I proteins presented CC by antigen presenting cells (APCs). In turn, recruits the Src CC kinase LCK to the vicinity of the TCR-CD3 complex. LCK then CC initiates different intracellular signaling pathways by CC phosphorylating various substrates ultimately leading to CC lymphokine production, motility, adhesion and activation of CC cytotoxic T-lymphocytes (CTLs). This mechanism enables CTLs to CC recognize and eliminate infected cells and tumor cells. In NK- CC cells, the presence of CD8A homodimers at the cell surface CC provides a survival mechanism allowing conjugation and lysis of CC multiple target cells. CD8A homodimer molecules also promote the CC survival and differentiation of activated lymphocytes into memory CC CD8 T-cells. {ECO:0000269|PubMed:16236125, CC ECO:0000269|PubMed:17678538, ECO:0000269|PubMed:23657257, CC ECO:0000269|PubMed:26082771}. CC -!- SUBUNIT: Forms disulfide-linked heterodimers with CD8B at the cell CC surface. Forms also homodimers in several cell types including NK- CC cells or peripheral blood T-lymphocytes. Interacts with the MHC CC class I HLA-A/B2M dimer. Interacts with LCK in a zinc-dependent CC manner. Interacts with HLA-G; this interaction is direct and might CC down-regulate T cell receptor signaling. CC {ECO:0000269|PubMed:12853576, ECO:0000269|PubMed:14500983, CC ECO:0000269|PubMed:6605969, ECO:0000269|PubMed:9177355}. CC -!- SUBCELLULAR LOCATION: Isoform 1: Cell membrane CC {ECO:0000269|PubMed:1460019, ECO:0000269|PubMed:17341584, CC ECO:0000269|PubMed:17678538}; Single-pass type I membrane protein. CC Note=CD8A localizes to lipid rafts only when associated with its CC partner CD8B. {ECO:0000269|PubMed:17341584}. CC -!- SUBCELLULAR LOCATION: Isoform 2: Secreted CC {ECO:0000269|PubMed:7923932}. CC -!- ALTERNATIVE PRODUCTS: CC Event=Alternative splicing; Named isoforms=3; CC Name=1; Synonyms=membrane, mCD8alpha; CC IsoId=P01732-1; Sequence=Displayed; CC Name=2; Synonyms=secreted, sCD8alpha; CC IsoId=P01732-2; Sequence=VSP_012653; CC Name=3; CC IsoId=P01732-3; Sequence=VSP_054438; CC Note=No experimental confirmation available.; CC -!- TISSUE SPECIFICITY: CD8 on thymus-derived T-cells usually consists CC of a disulfide-linked alpha/CD8A and a beta/CD8B chain. Less CC frequently, CD8 can be expressed as a CD8A homodimer. A subset of CC natural killer cells, memory T-cells, intraepithelial lymphocytes, CC monocytes and dendritic cells expresses CD8A homo-dimers. CC Expressed at the cell surface of plasmacytoid dendritic cells upon CC herpes simplex virus-1 stimulation. {ECO:0000269|PubMed:16236125, CC ECO:0000269|PubMed:17678538, ECO:0000269|PubMed:26082771}. CC -!- PTM: Palmitoylated, but association with CD8B seems to be more CC important for the enrichment of CD8A in lipid rafts. CC {ECO:0000269|PubMed:17341584}. CC -!- PTM: O-glycosylated. {ECO:0000269|PubMed:1460019}. CC -!- PTM: Phosphorylated in cytotoxic T-lymphocytes (CTLs) following CC activation. {ECO:0000269|PubMed:2512251}. CC -!- DISEASE: CD8 deficiency, familial (CD8 deficiency) [MIM:608957]: CC An immunologic defect characterized by absence of CD8+ cells, CC leading to recurrent bacterial infections. CC {ECO:0000269|PubMed:11435463}. Note=The disease is caused by CC mutations affecting the gene represented in this entry. CC -!- WEB RESOURCE: Name=CD8Abase; Note=CD8A mutation db; CC URL="http://structure.bmc.lu.se/idbase/CD8Abase/"; CC -!- WEB RESOURCE: Name=Wikipedia; Note=CD8 entry; CC URL="https://en.wikipedia.org/wiki/CD8"; 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; M26315; AAA79217.1; -; Genomic_DNA. DR EMBL; M26313; AAA79217.1; JOINED; Genomic_DNA. DR EMBL; M26314; AAA79217.1; JOINED; Genomic_DNA. DR EMBL; M26315; AAA79218.1; -; Genomic_DNA. DR EMBL; M26313; AAA79218.1; JOINED; Genomic_DNA. DR EMBL; M26314; AAA79218.1; JOINED; Genomic_DNA. DR EMBL; M12824; AAA61133.1; -; mRNA. DR EMBL; M12828; AAB04637.1; -; mRNA. DR EMBL; M27161; AAA59674.1; -; Genomic_DNA. DR EMBL; AK300089; BAG61892.1; -; mRNA. DR EMBL; AC064848; AAX88864.1; -; Genomic_DNA. DR EMBL; AC112696; -; NOT_ANNOTATED_CDS; Genomic_DNA. DR EMBL; CH471053; EAW99438.1; -; Genomic_DNA. DR EMBL; CH471053; EAW99439.1; -; Genomic_DNA. DR EMBL; CH471053; EAW99440.1; -; Genomic_DNA. DR CCDS; CCDS1992.1; -. [P01732-1] DR CCDS; CCDS1993.1; -. [P01732-2] DR PIR; A30604; RWHUT8. DR RefSeq; NP_001139345.1; NM_001145873.1. [P01732-1] DR RefSeq; NP_001759.3; NM_001768.6. [P01732-1] DR RefSeq; NP_741969.1; NM_171827.3. [P01732-2] DR UniGene; Hs.85258; -. DR PDB; 1AKJ; X-ray; 2.65 A; D/E=22-141. DR PDB; 1CD8; X-ray; 2.60 A; A=22-135. DR PDB; 1Q69; NMR; -; A=209-227. DR PDB; 2HP4; X-ray; 2.10 A; A/B=22-135. DR PDB; 3QZW; X-ray; 2.80 A; G/H/I/J=22-135. DR PDBsum; 1AKJ; -. DR PDBsum; 1CD8; -. DR PDBsum; 1Q69; -. DR PDBsum; 2HP4; -. DR PDBsum; 3QZW; -. DR ProteinModelPortal; P01732; -. DR SMR; P01732; -. DR BioGrid; 107363; 14. DR CORUM; P01732; -. DR IntAct; P01732; 7. DR STRING; 9606.ENSP00000283635; -. DR iPTMnet; P01732; -. DR PhosphoSitePlus; P01732; -. DR SwissPalm; P01732; -. DR BioMuta; CD8A; -. DR DMDM; 116035; -. DR jPOST; P01732; -. DR PaxDb; P01732; -. DR PeptideAtlas; P01732; -. DR PRIDE; P01732; -. DR ProteomicsDB; 51452; -. DR ProteomicsDB; 51453; -. [P01732-2] DR DNASU; 925; -. DR Ensembl; ENST00000283635; ENSP00000283635; ENSG00000153563. [P01732-1] DR Ensembl; ENST00000352580; ENSP00000321631; ENSG00000153563. [P01732-2] DR Ensembl; ENST00000409511; ENSP00000386559; ENSG00000153563. [P01732-1] DR GeneID; 925; -. DR KEGG; hsa:925; -. DR UCSC; uc002srt.4; human. [P01732-1] DR CTD; 925; -. DR DisGeNET; 925; -. DR EuPathDB; HostDB:ENSG00000153563.15; -. DR GeneCards; CD8A; -. DR HGNC; HGNC:1706; CD8A. DR HPA; CAB000012; -. DR HPA; CAB075722; -. DR HPA; HPA037756; -. DR MalaCards; CD8A; -. DR MIM; 186910; gene. DR MIM; 608957; phenotype. DR neXtProt; NX_P01732; -. DR OpenTargets; ENSG00000153563; -. DR Orphanet; 169085; Susceptibility to respiratory infections associated with CD8alpha chain mutation. DR PharmGKB; PA26244; -. DR eggNOG; ENOG410IWN3; Eukaryota. DR eggNOG; ENOG410Z6EI; LUCA. DR GeneTree; ENSGT00940000156588; -. DR HOGENOM; HOG000004794; -. DR HOVERGEN; HBG008488; -. DR InParanoid; P01732; -. DR KO; K06458; -. DR OMA; LYIWAPL; -. DR OrthoDB; 1448152at2759; -. DR PhylomeDB; P01732; -. DR TreeFam; TF336070; -. DR Reactome; R-HSA-198933; Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell. DR SIGNOR; P01732; -. DR ChiTaRS; CD8A; human. DR EvolutionaryTrace; P01732; -. DR GeneWiki; CD8A; -. DR GenomeRNAi; 925; -. DR PRO; PR:P01732; -. DR Proteomes; UP000005640; Chromosome 2. DR Bgee; ENSG00000153563; Expressed in 162 organ(s), highest expression level in thymus. DR ExpressionAtlas; P01732; baseline and differential. DR Genevisible; P01732; HS. DR GO; GO:0009897; C:external side of plasma membrane; IDA:MGI. DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell. DR GO; GO:0005887; C:integral component of plasma membrane; NAS:UniProtKB. DR GO; GO:0005886; C:plasma membrane; TAS:Reactome. DR GO; GO:0044853; C:plasma membrane raft; IDA:UniProtKB. DR GO; GO:0042101; C:T cell receptor complex; NAS:UniProtKB. DR GO; GO:0015026; F:coreceptor activity; NAS:UniProtKB. DR GO; GO:0042288; F:MHC class I protein binding; NAS:UniProtKB. DR GO; GO:0019901; F:protein kinase binding; IEA:Ensembl. DR GO; GO:0019882; P:antigen processing and presentation; NAS:UniProtKB. DR GO; GO:0007166; P:cell surface receptor signaling pathway; IBA:GO_Central. DR GO; GO:0045065; P:cytotoxic T cell differentiation; IBA:GO_Central. DR GO; GO:0006955; P:immune response; NAS:UniProtKB. DR GO; GO:0050776; P:regulation of immune response; TAS:Reactome. DR GO; GO:0042110; P:T cell activation; NAS:UniProtKB. DR GO; GO:0002456; P:T cell mediated immunity; IBA:GO_Central. DR GO; GO:0007169; P:transmembrane receptor protein tyrosine kinase signaling pathway; NAS:UniProtKB. DR Gene3D; 2.60.40.10; -; 1. DR InterPro; IPR015468; CD8_asu. DR InterPro; IPR007110; Ig-like_dom. DR InterPro; IPR036179; Ig-like_dom_sf. DR InterPro; IPR013783; Ig-like_fold. DR InterPro; IPR003599; Ig_sub. DR InterPro; IPR013106; Ig_V-set. DR PANTHER; PTHR10441; PTHR10441; 1. DR Pfam; PF07686; V-set; 1. DR SMART; SM00409; IG; 1. DR SMART; SM00406; IGv; 1. DR SUPFAM; SSF48726; SSF48726; 1. DR PROSITE; PS50835; IG_LIKE; 1. PE 1: Evidence at protein level; KW 3D-structure; Adaptive immunity; Alternative splicing; Cell membrane; KW Complete proteome; Disease mutation; Disulfide bond; Glycoprotein; KW Immunity; Immunoglobulin domain; Lipoprotein; Membrane; Palmitate; KW Reference proteome; Secreted; Signal; Transmembrane; KW Transmembrane helix. FT SIGNAL 1 21 FT CHAIN 22 235 T-cell surface glycoprotein CD8 alpha FT chain. FT /FTId=PRO_0000014638. FT TOPO_DOM 22 182 Extracellular. {ECO:0000255}. FT TRANSMEM 183 203 Helical. {ECO:0000255}. FT TOPO_DOM 204 235 Cytoplasmic. {ECO:0000255}. FT DOMAIN 22 135 Ig-like V-type. FT LIPID 206 206 S-palmitoyl cysteine. FT {ECO:0000269|PubMed:17341584}. FT DISULFID 43 115 {ECO:0000269|PubMed:1547508, FT ECO:0000269|PubMed:9177355}. FT VAR_SEQ 1 1 M -> MRNQAPGRPKGATFPPRRPTGSRAPPLAPELRAKQR FT PGERVM (in isoform 3). FT {ECO:0000303|PubMed:14702039}. FT /FTId=VSP_054438. FT VAR_SEQ 172 209 VHTRGLDFACDIYIWAPLAGTCGVLLLSLVITLYCNHR -> FT G (in isoform 2). {ECO:0000305}. FT /FTId=VSP_012653. FT VARIANT 111 111 G -> S (in CD8 deficiency; prevents CD8 FT expression; dbSNP:rs121918660). FT {ECO:0000269|PubMed:11435463}. FT /FTId=VAR_021020. FT MUTAGEN 111 111 G->R: Prevents CD8 expression. FT {ECO:0000269|PubMed:11435463}. FT MUTAGEN 206 206 C->A: Complete loss of palmitoylation. FT {ECO:0000269|PubMed:17341584}. FT STRAND 24 27 {ECO:0000244|PDB:2HP4}. FT STRAND 39 45 {ECO:0000244|PDB:2HP4}. FT STRAND 54 64 {ECO:0000244|PDB:2HP4}. FT STRAND 68 77 {ECO:0000244|PDB:2HP4}. FT TURN 86 88 {ECO:0000244|PDB:2HP4}. FT STRAND 89 94 {ECO:0000244|PDB:2HP4}. FT STRAND 97 104 {ECO:0000244|PDB:2HP4}. FT HELIX 107 109 {ECO:0000244|PDB:2HP4}. FT STRAND 111 119 {ECO:0000244|PDB:2HP4}. FT STRAND 122 125 {ECO:0000244|PDB:2HP4}. FT STRAND 129 131 {ECO:0000244|PDB:2HP4}. SQ SEQUENCE 235 AA; 25729 MW; FCCA29BAA73726BB CRC64; MALPVTALLL PLALLLHAAR PSQFRVSPLD RTWNLGETVE LKCQVLLSNP TSGCSWLFQP RGAAASPTFL LYLSQNKPKA AEGLDTQRFS GKRLGDTFVL TLSDFRRENE GYYFCSALSN SIMYFSHFVP VFLPAKPTTT PAPRPPTPAP TIASQPLSLR PEACRPAAGG AVHTRGLDFA CDIYIWAPLA GTCGVLLLSL VITLYCNHRN RRRVCKCPRP VVKSGDKPSL SARYV //