ID   F7CGN8_HORSE            Unreviewed;       213 AA.
AC   F7CGN8;
DT   27-JUL-2011, integrated into UniProtKB/TrEMBL.
DT   13-SEP-2023, sequence version 2.
DT   02-SEP-2026, entry version 78.
DE   RecName: Full=B-cell antigen receptor complex-associated protein alpha chain {ECO:0000256|ARBA:ARBA00074220};
DE   AltName: Full=Ig-alpha {ECO:0000256|ARBA:ARBA00079134};
GN   Name=CD79A {ECO:0000313|VGNC:VGNC:16279};
OS   Equus caballus (Horse).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Perissodactyla; Equidae; Equus.
OX   NCBI_TaxID=9796 {ECO:0000313|Ensembl:ENSECAP00000005291.2, ECO:0000313|Proteomes:UP000002281};
RN   [1] {ECO:0000313|Ensembl:ENSECAP00000005291.2, ECO:0000313|Proteomes:UP000002281}
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Thoroughbred {ECO:0000313|Ensembl:ENSECAP00000005291.2,
RC   ECO:0000313|Proteomes:UP000002281};
RX   PubMed=19892987; DOI=10.1126/science.1178158;
RG   Broad Institute Genome Sequencing Platform;
RG   Broad Institute Whole Genome Assembly Team;
RA   Wade C.M., Giulotto E., Sigurdsson S., Zoli M., Gnerre S., Imsland F.,
RA   Lear T.L., Adelson D.L., Bailey E., Bellone R.R., Bloecker H., Distl O.,
RA   Edgar R.C., Garber M., Leeb T., Mauceli E., MacLeod J.N., Penedo M.C.T.,
RA   Raison J.M., Sharpe T., Vogel J., Andersson L., Antczak D.F., Biagi T.,
RA   Binns M.M., Chowdhary B.P., Coleman S.J., Della Valle G., Fryc S.,
RA   Guerin G., Hasegawa T., Hill E.W., Jurka J., Kiialainen A., Lindgren G.,
RA   Liu J., Magnani E., Mickelson J.R., Murray J., Nergadze S.G., Onofrio R.,
RA   Pedroni S., Piras M.F., Raudsepp T., Rocchi M., Roeed K.H., Ryder O.A.,
RA   Searle S., Skow L., Swinburne J.E., Syvaenen A.C., Tozaki T., Valberg S.J.,
RA   Vaudin M., White J.R., Zody M.C., Lander E.S., Lindblad-Toh K.;
RT   "Genome sequence, comparative analysis, and population genetics of the
RT   domestic horse.";
RL   Science 326:865-867(2009).
RN   [2] {ECO:0000313|Ensembl:ENSECAP00000005291.2}
RP   IDENTIFICATION.
RC   STRAIN=Thoroughbred {ECO:0000313|Ensembl:ENSECAP00000005291.2};
RG   Ensembl;
RL   Submitted (JAN-2026) to UniProtKB.
CC   -!- FUNCTION: Required in cooperation with CD79B for initiation of the
CC       signal transduction cascade activated by binding of antigen to the B-
CC       cell antigen receptor complex (BCR) which leads to internalization of
CC       the complex, trafficking to late endosomes and antigen presentation.
CC       Also required for BCR surface expression and for efficient
CC       differentiation of pro- and pre-B-cells. Stimulates SYK
CC       autophosphorylation and activation. Binds to BLNK, bringing BLNK into
CC       proximity with SYK and allowing SYK to phosphorylate BLNK. Also
CC       interacts with and increases activity of some Src-family tyrosine
CC       kinases. Represses BCR signaling during development of immature B-
CC       cells. {ECO:0000256|ARBA:ARBA00059989}.
CC   -!- SUBUNIT: Heterodimer of alpha and beta chains; disulfide-linked. Part
CC       of the B-cell antigen receptor complex where the alpha/beta chain
CC       heterodimer is non-covalently associated with an antigen-specific
CC       membrane-bound surface immunoglobulin of two heavy chains and two light
CC       chains. Interacts through its phosphorylated ITAM domain with the SH2
CC       domains of SYK which stimulates SYK autophosphorylation and activation.
CC       Also interacts, when phosphorylated on Tyr-207, with the SH2 domain of
CC       BLNK/SLP65, bringing BLNK into proximity with SYK and allowing SYK to
CC       phosphorylate BLNK which is necessary for trafficking of the BCR to
CC       late endosomes. Interacts with Src-family tyrosine kinases including
CC       FYN and LYN, increasing their activity.
CC       {ECO:0000256|ARBA:ARBA00062492}.
CC   -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000256|ARBA:ARBA00004251};
CC       Single-pass type I membrane protein {ECO:0000256|ARBA:ARBA00004251}.
CC   -!- CAUTION: Lacks conserved residue(s) required for the propagation of
CC       feature annotation. {ECO:0000256|PROSITE-ProRule:PRU00114}.
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DR   AlphaFoldDB; F7CGN8; -.
DR   FunCoup; F7CGN8; 301.
DR   STRING; 9796.ENSECAP00000005291; -.
DR   PaxDb; 9796-ENSECAP00000005291; -.
DR   Ensembl; ENSECAT00000007284.3; ENSECAP00000005291.2; ENSECAG00000007198.4.
DR   VGNC; VGNC:16279; CD79A.
DR   GeneTree; ENSGT00940000154363; -.
DR   HOGENOM; CLU_106774_0_0_1; -.
DR   InParanoid; F7CGN8; -.
DR   Proteomes; UP000002281; Chromosome 10.
DR   Bgee; ENSECAG00000007198; Expressed in leukocyte and 16 other cell types or tissues.
DR   ExpressionAtlas; F7CGN8; baseline.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0004888; F:transmembrane signaling receptor activity; IEA:InterPro.
DR   GO; GO:0007166; P:cell surface receptor signaling pathway; IEA:InterPro.
DR   CDD; cd00096; Ig; 1.
DR   FunFam; 2.60.40.10:FF:001852; B-cell antigen receptor complex-associated protein alpha chain; 1.
DR   Gene3D; 2.60.40.10; Immunoglobulins; 1.
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; IPR003110; Phos_immunorcpt_sig_ITAM.
DR   PANTHER; PTHR14334; B-CELL ANTIGEN RECEPTOR COMPLEX-ASSOCIATED PROTEIN; 1.
DR   PANTHER; PTHR14334:SF1; B-CELL ANTIGEN RECEPTOR COMPLEX-ASSOCIATED PROTEIN ALPHA CHAIN; 1.
DR   Pfam; PF13927; Ig_3; 1.
DR   Pfam; PF02189; ITAM; 1.
DR   SMART; SM00409; IG; 1.
DR   SMART; SM00077; ITAM; 1.
DR   SUPFAM; SSF48726; Immunoglobulin; 1.
DR   PROSITE; PS50835; IG_LIKE; 1.
DR   PROSITE; PS51055; ITAM_1; 1.
PE   4: Predicted;
KW   Adaptive immunity {ECO:0000256|ARBA:ARBA00023130};
KW   Cell membrane {ECO:0000256|ARBA:ARBA00022475};
KW   Disulfide bond {ECO:0000256|ARBA:ARBA00023157};
KW   Glycoprotein {ECO:0000256|ARBA:ARBA00023180};
KW   Immunity {ECO:0000256|ARBA:ARBA00022859};
KW   Immunoglobulin domain {ECO:0000256|ARBA:ARBA00023319, ECO:0000256|PROSITE-
KW   ProRule:PRU00114};
KW   Membrane {ECO:0000256|ARBA:ARBA00023136, ECO:0000256|SAM:Phobius};
KW   Methylation {ECO:0000256|ARBA:ARBA00022481};
KW   Phosphoprotein {ECO:0000256|ARBA:ARBA00022553};
KW   Receptor {ECO:0000256|ARBA:ARBA00023170};
KW   Reference proteome {ECO:0000313|Proteomes:UP000002281};
KW   Signal {ECO:0000256|ARBA:ARBA00022729, ECO:0000256|SAM:SignalP};
KW   Transmembrane {ECO:0000256|ARBA:ARBA00022692, ECO:0000256|SAM:Phobius};
KW   Transmembrane helix {ECO:0000256|ARBA:ARBA00022989,
KW   ECO:0000256|SAM:Phobius}; Ubl conjugation {ECO:0000256|ARBA:ARBA00022843}.
FT   SIGNAL          1..28
FT                   /evidence="ECO:0000256|SAM:SignalP"
FT   CHAIN           29..213
FT                   /note="B-cell antigen receptor complex-associated protein
FT                   alpha chain"
FT                   /evidence="ECO:0000256|SAM:SignalP"
FT                   /id="PRO_5040135397"
FT   TRANSMEM        131..152
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|SAM:Phobius"
FT   DOMAIN          11..105
FT                   /note="Ig-like"
FT                   /evidence="ECO:0000259|PROSITE:PS50835"
FT   MOD_RES         175
FT                   /note="Phosphotyrosine"
FT                   /evidence="ECO:0000256|PROSITE-ProRule:PRU00379"
FT   MOD_RES         186
FT                   /note="Phosphotyrosine"
FT                   /evidence="ECO:0000256|PROSITE-ProRule:PRU00379"
SQ   SEQUENCE   213 AA;  23662 MW;  B2859A2FFEBCBAC7 CRC64;
     MPGAPGVLQA PPATLFLLFL ISAAGVVTVS VGDEARLQCK HNGSSPGSHI NITWWRILQS
     NFTWPPMFLE YGKGPMGELT IQQVNKSHGG MYRCQAKEGN ETKQSCGTYL RVREPLPRPF
     LDMGEGTKNN IITAEGIILL FCAVVPGTLL LFRKRWQNLK FGPDIQDDYE DENLYEGLNL
     DDCSMYEDIS RGLQGTYQDV GSLHIGDVQL EKP
//