CD8A_BOVIN
ID CD8A_BOVIN Reviewed; 242 AA.
AC P31783;
DT 01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT 01-JUL-1993, sequence version 1.
DT 25-MAY-2022, entry version 123.
DE RecName: Full=T-cell surface glycoprotein CD8 alpha chain;
DE AltName: CD_antigen=CD8a;
DE Flags: Precursor;
GN Name=CD8A;
OS Bos taurus (Bovine).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae;
OC Bovinae; Bos.
OX NCBI_TaxID=9913;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Thymus;
RX PubMed=1628904;
RA Lalor P., Bucci C., Fornaro M., Rattazzi M.C., Nakauchi H.,
RA Herzenberg L.A., Alberti S.;
RT "Molecular cloning, reconstruction and expression of the gene encoding the
RT alpha-chain of the bovine CD8 -- definition of three peptide regions
RT conserved across species.";
RL Immunology 76:95-102(1992).
CC -!- FUNCTION: Integral membrane glycoprotein that plays an essential role
CC in the immune response and serves multiple functions in responses
CC against both external and internal offenses. In T-cells, functions
CC primarily as a coreceptor for MHC class I molecule:peptide complex. The
CC antigens presented by class I peptides are derived from cytosolic
CC proteins while class II derived from extracellular proteins. Interacts
CC simultaneously with the T-cell receptor (TCR) and the MHC class I
CC proteins presented by antigen presenting cells (APCs). In turn,
CC recruits the Src kinase LCK to the vicinity of the TCR-CD3 complex. LCK
CC then initiates different intracellular signaling pathways by
CC phosphorylating various substrates ultimately leading to lymphokine
CC production, motility, adhesion and activation of cytotoxic T-
CC lymphocytes (CTLs). This mechanism enables CTLs to recognize and
CC eliminate infected cells and tumor cells. In NK-cells, the presence of
CC CD8A homodimers at the cell surface provides a survival mechanism
CC allowing conjugation and lysis of multiple target cells. CD8A homodimer
CC molecules also promote the survival and differentiation of activated
CC lymphocytes into memory CD8 T-cells. {ECO:0000250|UniProtKB:P01732}.
CC -!- SUBUNIT: Forms disulfide-linked heterodimers with CD8B at the cell
CC surface. Forms also homodimers in several cell types including NK-cells
CC or peripheral blood T-lymphocytes. Interacts with the MHC class I HLA-
CC A/B2M dimer. Interacts with LCK in a zinc-dependent manner.
CC {ECO:0000250|UniProtKB:P01732}.
CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000250|UniProtKB:P01732};
CC Single-pass type I membrane protein {ECO:0000250|UniProtKB:P01732}.
CC Note=CD8A localizes to lipid rafts only when associated with its
CC partner CD8B. {ECO:0000250|UniProtKB:P01732}.
CC -!- PTM: Palmitoylated, but association with CD8B seems to be more
CC important for the enrichment of CD8A in lipid rafts.
CC {ECO:0000250|UniProtKB:P01732}.
CC -!- PTM: O-glycosylated. {ECO:0000250|UniProtKB:P01732}.
CC -!- PTM: Phosphorylated in cytotoxic T-lymphocytes (CTLs) following
CC activation. {ECO:0000250|UniProtKB:P01732}.
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DR EMBL; X59416; CAA42051.1; -; mRNA.
DR PIR; S25663; S25663.
DR RefSeq; NP_776440.1; NM_174015.1.
DR PDB; 5EBG; X-ray; 1.80 A; A/B=25-139.
DR PDBsum; 5EBG; -.
DR AlphaFoldDB; P31783; -.
DR SMR; P31783; -.
DR STRING; 9913.ENSBTAP00000028175; -.
DR PaxDb; P31783; -.
DR ABCD; P31783; 1 sequenced antibody.
DR GeneID; 281060; -.
DR KEGG; bta:281060; -.
DR CTD; 925; -.
DR eggNOG; ENOG502SAZN; Eukaryota.
DR InParanoid; P31783; -.
DR OrthoDB; 1448152at2759; -.
DR Proteomes; UP000009136; Unplaced.
DR GO; GO:0009897; C:external side of plasma membrane; IBA:GO_Central.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
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:0002456; P:T cell mediated immunity; IBA:GO_Central.
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; Cell membrane; Disulfide bond;
KW Glycoprotein; Immunity; Immunoglobulin domain; Lipoprotein; Membrane;
KW Palmitate; Reference proteome; Signal; Transmembrane; Transmembrane helix.
FT SIGNAL 1..25
FT /evidence="ECO:0000255"
FT CHAIN 26..242
FT /note="T-cell surface glycoprotein CD8 alpha chain"
FT /id="PRO_0000014635"
FT TOPO_DOM 26..189
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT TRANSMEM 190..214
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 215..242
FT /note="Cytoplasmic"
FT /evidence="ECO:0000255"
FT DOMAIN 26..140
FT /note="Ig-like V-type"
FT REGION 147..166
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 149..166
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT LIPID 213
FT /note="S-palmitoyl cysteine"
FT /evidence="ECO:0000250|UniProtKB:P01732"
FT DISULFID 47..120
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114"
FT STRAND 28..33
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 43..51
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 58..63
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 65..67
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 72..80
FT /evidence="ECO:0007829|PDB:5EBG"
FT TURN 90..92
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 93..97
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 99..109
FT /evidence="ECO:0007829|PDB:5EBG"
FT HELIX 112..114
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 116..124
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 127..130
FT /evidence="ECO:0007829|PDB:5EBG"
FT STRAND 134..137
FT /evidence="ECO:0007829|PDB:5EBG"
SQ SEQUENCE 242 AA; 26417 MW; 91481320EF05195E CRC64;
MASLLTALIL PLALLLLDAA KVLGSLSFRM SPTQKETRLG EKVELQCELL QSGMATGCSW
LRHIPGDDPR PTFLMYLSAQ RVKLAEGLDP RHISGAKVSG TKFQLTLSSF LQEDQGYYFC
SVVSNSILYF SNFVPVFLPA KPATTPAMRP SSAAPTSAPQ TRSVSPRSEV CRTSAGSAVD
TSRLDFACNI YIWAPLVGTC GVLLLSLVIT GICYRRNRRR VCKCPRPVVR QGGKPNLSEK
YV
