ID   CTLA4_PIG               Reviewed;         223 AA.
AC   Q9MYX7;
DT   01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2000, sequence version 1.
DT   25-MAY-2022, entry version 108.
DE   RecName: Full=Cytotoxic T-lymphocyte protein 4;
DE   AltName: Full=Cytotoxic T-lymphocyte-associated antigen 4;
DE            Short=CTLA-4;
DE   AltName: CD_antigen=CD152;
DE   Flags: Precursor;
GN   Name=CTLA4;
OS   Sus scrofa (Pig).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Artiodactyla; Suina; Suidae; Sus.
OX   NCBI_TaxID=9823;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RA   Tachedjian M., Chaplin P.J., Scheerlinck J.-P.Y., Tennent J.M.;
RT   "Molecular characterization and phylogenetic analysis of porcine cytotoxic
RT   T-lymphocyte-associated antigen 4 (CTLA4).";
RL   Submitted (JUN-2000) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Inhibitory receptor acting as a major negative regulator of
CC       T-cell responses. The affinity of CTLA4 for its natural B7 family
CC       ligands, CD80 and CD86, is considerably stronger than the affinity of
CC       their cognate stimulatory coreceptor CD28.
CC       {ECO:0000250|UniProtKB:P16410}.
CC   -!- SUBUNIT: Homodimer; disulfide-linked. Binds to CD80/B7-1 and CD86/B7.2.
CC       Interacts with ICOSLG. {ECO:0000250|UniProtKB:P16410}.
CC   -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000250|UniProtKB:P16410};
CC       Single-pass type I membrane protein {ECO:0000250|UniProtKB:P16410}.
CC       Note=Exists primarily an intracellular antigen whose surface expression
CC       is tightly regulated by restricted trafficking to the cell surface and
CC       rapid internalization. {ECO:0000250|UniProtKB:P16410}.
CC   -!- PTM: N-glycosylation is important for dimerization.
CC       {ECO:0000250|UniProtKB:P16410}.
CC   -!- PTM: Phosphorylation at Tyr-201 prevents binding to the AP-2 adapter
CC       complex, blocks endocytosis, and leads to retention of CTLA4 on the
CC       cell surface. {ECO:0000250|UniProtKB:P16410}.
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DR   EMBL; AF281633; AAF86981.1; -; mRNA.
DR   AlphaFoldDB; Q9MYX7; -.
DR   SMR; Q9MYX7; -.
DR   STRING; 9823.ENSSSCP00000031088; -.
DR   PaxDb; Q9MYX7; -.
DR   eggNOG; ENOG502RZVK; Eukaryota.
DR   InParanoid; Q9MYX7; -.
DR   Proteomes; UP000008227; Unplaced.
DR   Proteomes; UP000314985; Unplaced.
DR   GO; GO:0009897; C:external side of plasma membrane; IBA:GO_Central.
DR   GO; GO:0005887; C:integral component of plasma membrane; ISS:UniProtKB.
DR   GO; GO:0002250; P:adaptive immune response; IEA:UniProtKB-KW.
DR   GO; GO:0050853; P:B cell receptor signaling pathway; IBA:GO_Central.
DR   GO; GO:0045590; P:negative regulation of regulatory T cell differentiation; IBA:GO_Central.
DR   GO; GO:0042129; P:regulation of T cell proliferation; IEA:InterPro.
DR   GO; GO:0050852; P:T cell receptor signaling pathway; IBA:GO_Central.
DR   Gene3D; 2.60.40.10; -; 1.
DR   InterPro; IPR008096; CTLA4.
DR   InterPro; IPR040216; CTLA4/CD28.
DR   InterPro; IPR036179; Ig-like_dom_sf.
DR   InterPro; IPR013783; Ig-like_fold.
DR   InterPro; IPR013106; Ig_V-set.
DR   PANTHER; PTHR11494; PTHR11494; 1.
DR   PANTHER; PTHR11494:SF8; PTHR11494:SF8; 1.
DR   Pfam; PF07686; V-set; 1.
DR   PRINTS; PR01720; CTLANTIGEN4.
DR   SUPFAM; SSF48726; SSF48726; 1.
PE   2: Evidence at transcript level;
KW   Adaptive immunity; Cell membrane; Disulfide bond; Glycoprotein; Immunity;
KW   Immunoglobulin domain; Membrane; Phosphoprotein; Reference proteome;
KW   Signal; Transmembrane; Transmembrane helix.
FT   SIGNAL          1..35
FT                   /evidence="ECO:0000255"
FT   CHAIN           36..223
FT                   /note="Cytotoxic T-lymphocyte protein 4"
FT                   /id="PRO_0000014736"
FT   TOPO_DOM        38..161
FT                   /note="Extracellular"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        162..182
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        183..223
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          39..140
FT                   /note="Ig-like V-type"
FT   REGION          46..50
FT                   /note="Homodimerization"
FT                   /evidence="ECO:0000250|UniProtKB:P16410"
FT   REGION          134..139
FT                   /note="Important for interaction with CD80 and CD86"
FT                   /evidence="ECO:0000250|UniProtKB:P16410"
FT   REGION          150..155
FT                   /note="Homodimerization"
FT                   /evidence="ECO:0000250|UniProtKB:P16410"
FT   MOD_RES         201
FT                   /note="Phosphotyrosine; by TXK and JAK2"
FT                   /evidence="ECO:0000250|UniProtKB:P16410"
FT   CARBOHYD        113
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        145
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   DISULFID        58..129
FT                   /evidence="ECO:0000250|UniProtKB:P16410"
FT   DISULFID        85..103
FT                   /evidence="ECO:0000250|UniProtKB:P16410"
FT   DISULFID        157
FT                   /note="Interchain"
FT                   /evidence="ECO:0000250|UniProtKB:P16410"
SQ   SEQUENCE   223 AA;  24430 MW;  2DDB865D871D8921 CRC64;
     MACSGFQSHG AWLELTSRTW PCTALFSLLF IPVFSKGMHV AQPAVVLANS RGVASFVCEY
     GSAGKAAEVR VTVLRRAGSQ MTEVCAATYT VEDELTFLDD STCTGTSTEN KVNLTIQGLR
     AVDTGLYICK VELLYPPPYY VGMGNGTQIY VIDPEPCPDS DFLLWILAAV SSGLFFYSFL
     ITAVSLSKML KKRSPLTTGV YVKMPPTEPE CEKQFQPYFI PIN