ID CD79A_HUMAN Reviewed; 226 AA. AC P11912; A0N775; Q53FB8; DT 01-OCT-1989, integrated into UniProtKB/Swiss-Prot. DT 01-JUN-1994, sequence version 2. DT 24-JAN-2024, entry version 210. DE RecName: Full=B-cell antigen receptor complex-associated protein alpha chain; DE AltName: Full=Ig-alpha; DE AltName: Full=MB-1 membrane glycoprotein; DE AltName: Full=Membrane-bound immunoglobulin-associated protein; DE AltName: Full=Surface IgM-associated protein; DE AltName: CD_antigen=CD79a; DE Flags: Precursor; GN Name=CD79A; Synonyms=IGA, MB1; 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] (ISOFORM 1). RX PubMed=1395095; DOI=10.1111/j.1365-2249.1992.tb05846.x; RA Leduc I., Preud'Homme J.L., Cogne M.; RT "Structure and expression of the mb-1 transcript in human lymphoid cells."; RL Clin. Exp. Immunol. 90:141-146(1992). RN [2] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). RC TISSUE=Tonsil; RX PubMed=1534761; DOI=10.1002/eji.1830220641; RA Mueller B.S., Cooper L., Terhorst C.; RT "Cloning and sequencing of the cDNA encoding the human homologue of the RT murine immunoglobulin-associated protein B29."; RL Eur. J. Immunol. 22:1621-1625(1992). RN [3] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). RX PubMed=1639443; DOI=10.1007/bf00215058; RA Flaswinkel H., Reth M.; RT "Molecular cloning of the Ig-alpha subunit of the human B-cell antigen RT receptor complex."; RL Immunogenetics 36:266-269(1992). RN [4] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). RX PubMed=1729378; RA Yu L.M., Chang T.W.; RT "Human mb-1 gene: complete cDNA sequence and its expression in B cells RT bearing membrane Ig of various isotypes."; RL J. Immunol. 148:633-637(1992). RN [5] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA] (ISOFORM 1). RX PubMed=1538135; RA Ha H.J., Kubagawa H., Burrows P.D.; RT "Molecular cloning and expression pattern of a human gene homologous to the RT murine mb-1 gene."; RL J. Immunol. 148:1526-1531(1992). RN [6] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORM 1). RX PubMed=7916003; DOI=10.1007/bf00189974; RA Hashimoto S., Mohrenweiser H.W., Gregersen P.K., Chiorazzi N.; RT "Chromosomal localization, genomic structure, and allelic polymorphism of RT the human CD79 alpha (Ig-alpha/mb-1) gene."; RL Immunogenetics 40:287-295(1994). RN [7] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=8207205; RA Ha H., Barnoski B.L., Sun L., Emanuel B.S., Burrows P.D.; RT "Structure, chromosomal localization, and methylation pattern of the human RT mb-1 gene."; RL J. Immunol. 152:5749-5757(1994). RN [8] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 2). RX PubMed=7643857; DOI=10.1016/0161-5890(95)00023-8; RA Hashimoto S., Chiorazzi N., Gregersen P.K.; RT "Alternative splicing of CD79a (Ig-alpha/mb-1) and CD79b (Ig-beta/B29) RNA RT transcripts in human B cells."; RL Mol. Immunol. 32:651-659(1995). RN [9] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 2). RA Koyama M., Nakamura T.; RL Submitted (DEC-1994) to the EMBL/GenBank/DDBJ databases. RN [10] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1). RC TISSUE=Small intestine; RA Totoki Y., Toyoda A., Takeda T., Sakaki Y., Tanaka A., Yokoyama S.; RL Submitted (APR-2005) to the EMBL/GenBank/DDBJ databases. RN [11] RP PROTEIN SEQUENCE OF 33-52. RX PubMed=7514267; DOI=10.1016/0161-5890(94)90061-2; RA Vasile S., Coligan J.E., Yoshida M., Seon B.K.; RT "Isolation and chemical characterization of the human B29 and mb-1 proteins RT of the B cell antigen receptor complex."; RL Mol. Immunol. 31:419-427(1994). RN [12] RP PRELIMINARY NUCLEOTIDE SEQUENCE [MRNA] OF 190-226 (ISOFORM 1). RX PubMed=2463161; DOI=10.1002/j.1460-2075.1988.tb03220.x; RA Sakaguchi N., Kashiwamura S., Kimoto M., Thalmann P., Melchers F.; RT "B lymphocyte lineage-restricted expression of mb-1, a gene with CD3-like RT structural properties."; RL EMBO J. 7:3457-3464(1988). RN [13] RP FUNCTION. RX PubMed=8617796; DOI=10.1074/jbc.271.9.5158; RA Luisiri P., Lee Y.J., Eisfelder B.J., Clark M.R.; RT "Cooperativity and segregation of function within the Ig-alpha/beta RT heterodimer of the B cell antigen receptor complex."; RL J. Biol. Chem. 271:5158-5163(1996). RN [14] RP FUNCTION. RX PubMed=9057631; RA Tseng J., Eisfelder B.J., Clark M.R.; RT "B-cell antigen receptor-induced apoptosis requires both Ig alpha and Ig RT beta."; RL Blood 89:1513-1520(1997). RN [15] RP INVOLVEMENT IN AGM3. RX PubMed=10525050; DOI=10.1172/jci7696; RA Minegishi Y., Coustan-Smith E., Rapalus L., Ersoy F., Campana D., RA Conley M.E.; RT "Mutations in Igalpha (CD79a) result in a complete block in B-cell RT development."; RL J. Clin. Invest. 104:1115-1121(1999). RN [16] RP PHOSPHORYLATION, AND MUTAGENESIS OF SER-197; SER-203 AND THR-209. RX PubMed=10900006; DOI=10.1073/pnas.97.15.8451; RA Mueller R., Wienands J., Reth M.; RT "The serine and threonine residues in the Ig-alpha cytoplasmic tail RT negatively regulate immunoreceptor tyrosine-based activation motif-mediated RT signal transduction."; RL Proc. Natl. Acad. Sci. U.S.A. 97:8451-8454(2000). RN [17] RP INVOLVEMENT IN AGM3. RX PubMed=11920841; DOI=10.1002/ajmg.10296; RA Wang Y., Kanegane H., Sanal O., Tezcan I., Ersoy F., Futatani T., RA Miyawaki T.; RT "Novel Igalpha (CD79a) gene mutation in a Turkish patient with B cell- RT deficient agammaglobulinemia."; RL Am. J. Med. Genet. 108:333-336(2002). RN [18] RP STRUCTURE BY NMR OF 184-195, PHOSPHORYLATION, AND INTERACTION WITH LYN. RX PubMed=10748115; DOI=10.1074/jbc.m909044199; RA Gaul B.S., Harrison M.L., Geahlen R.L., Burton R.A., Post C.B.; RT "Substrate recognition by the Lyn protein-tyrosine kinase. NMR structure of RT the immunoreceptor tyrosine-based activation motif signaling region of the RT B cell antigen receptor."; RL J. Biol. Chem. 275:16174-16182(2000). RN [19] RP STRUCTURE BY ELECTRON MICROSCOPY (3.30 ANGSTROMS) IN COMPLEX WITH CD79B AND RP IMMUNOGLOBULIN M, DISULFIDE BOND, SUBUNIT, DOMAIN, CHARACTERIZATION OF IGM RP BCR, GLYCOSYLATION AT ASN-57; ASN-63; ASN-73; ASN-88; ASN-97 AND ASN-112, RP AND MUTAGENESIS OF LEU-152 AND ALA-156. RX PubMed=35981043; DOI=10.1126/science.abo3923; RA Su Q., Chen M., Shi Y., Zhang X., Huang G., Huang B., Liu D., Liu Z., RA Shi Y.; RT "Cryo-EM structure of the human IgM B cell receptor."; RL Science 377:875-880(2022). 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:0000269|PubMed:8617796, ECO:0000269|PubMed:9057631}. 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 (PubMed:35981043). Interacts through its phosphorylated ITAM CC domain with the SH2 domains of SYK which stimulates SYK CC autophosphorylation and activation. Also interacts, when phosphorylated CC on Tyr-210, with the SH2 domain of BLNK/SLP65, bringing BLNK into CC proximity with SYK and allowing SYK to phosphorylate BLNK which is CC necessary for trafficking of the BCR to late endosomes. Interacts with CC Src-family tyrosine kinases including FYN and LYN, increasing their CC activity (By similarity). {ECO:0000250, ECO:0000269|PubMed:35981043}. CC -!- INTERACTION: CC P11912; Q15848: ADIPOQ; NbExp=3; IntAct=EBI-7797864, EBI-10827839; CC P11912; Q6RW13-2: AGTRAP; NbExp=3; IntAct=EBI-7797864, EBI-11522760; CC P11912; Q5BKT4: ALG10; NbExp=3; IntAct=EBI-7797864, EBI-13064220; CC P11912; Q5I7T1: ALG10B; NbExp=3; IntAct=EBI-7797864, EBI-18075734; CC P11912; Q92685: ALG3; NbExp=3; IntAct=EBI-7797864, EBI-2848814; CC P11912; P05090: APOD; NbExp=3; IntAct=EBI-7797864, EBI-715495; CC P11912; P29972: AQP1; NbExp=3; IntAct=EBI-7797864, EBI-745213; CC P11912; Q92482: AQP3; NbExp=3; IntAct=EBI-7797864, EBI-2808854; CC P11912; P27449: ATP6V0C; NbExp=3; IntAct=EBI-7797864, EBI-721179; CC P11912; Q92843: BCL2L2; NbExp=3; IntAct=EBI-7797864, EBI-707714; CC P11912; O15155: BET1; NbExp=3; IntAct=EBI-7797864, EBI-749204; CC P11912; Q6PL45-2: BRICD5; NbExp=3; IntAct=EBI-7797864, EBI-12244618; CC P11912; Q8WVV5: BTN2A2; NbExp=3; IntAct=EBI-7797864, EBI-8648738; CC P11912; O14523: C2CD2L; NbExp=3; IntAct=EBI-7797864, EBI-12822627; CC P11912; Q8WVX3-2: C4orf3; NbExp=3; IntAct=EBI-7797864, EBI-12003442; CC P11912; Q9P0B6: CCDC167; NbExp=3; IntAct=EBI-7797864, EBI-9083477; CC P11912; O14735: CDIPT; NbExp=3; IntAct=EBI-7797864, EBI-358858; CC P11912; O95832: CLDN1; NbExp=3; IntAct=EBI-7797864, EBI-723889; CC P11912; Q9NWW5: CLN6; NbExp=3; IntAct=EBI-7797864, EBI-6165897; CC P11912; Q96DZ9-2: CMTM5; NbExp=3; IntAct=EBI-7797864, EBI-11522780; CC P11912; Q96FZ5: CMTM7; NbExp=3; IntAct=EBI-7797864, EBI-2807956; CC P11912; O95406: CNIH1; NbExp=3; IntAct=EBI-7797864, EBI-12172273; CC P11912; Q8TBE1: CNIH3; NbExp=3; IntAct=EBI-7797864, EBI-12208021; CC P11912; P29400-2: COL4A5; NbExp=3; IntAct=EBI-7797864, EBI-12211159; CC P11912; Q4LDR2: CTXN3; NbExp=3; IntAct=EBI-7797864, EBI-12019274; CC P11912; P49447: CYB561; NbExp=3; IntAct=EBI-7797864, EBI-8646596; CC P11912; Q8NBI2: CYB561A3; NbExp=3; IntAct=EBI-7797864, EBI-10269179; CC P11912; O14569: CYB561D2; NbExp=3; IntAct=EBI-7797864, EBI-717654; CC P11912; O43169: CYB5B; NbExp=3; IntAct=EBI-7797864, EBI-1058710; CC P11912; Q9H1M4: DEFB127; NbExp=3; IntAct=EBI-7797864, EBI-10305240; CC P11912; Q9UPQ8: DOLK; NbExp=3; IntAct=EBI-7797864, EBI-8645574; CC P11912; P56851: EDDM3B; NbExp=3; IntAct=EBI-7797864, EBI-10215665; CC P11912; Q9BV81: EMC6; NbExp=3; IntAct=EBI-7797864, EBI-2820492; CC P11912; P54849: EMP1; NbExp=3; IntAct=EBI-7797864, EBI-4319440; CC P11912; P54852: EMP3; NbExp=3; IntAct=EBI-7797864, EBI-3907816; CC P11912; Q7L5A8: FA2H; NbExp=3; IntAct=EBI-7797864, EBI-11337888; CC P11912; Q96D05-2: FAM241B; NbExp=3; IntAct=EBI-7797864, EBI-12118888; CC P11912; Q969F0: FATE1; NbExp=6; IntAct=EBI-7797864, EBI-743099; CC P11912; Q96IV6: FAXDC2; NbExp=3; IntAct=EBI-7797864, EBI-12142299; CC P11912; P37268: FDFT1; NbExp=3; IntAct=EBI-7797864, EBI-714550; CC P11912; O14843: FFAR3; NbExp=3; IntAct=EBI-7797864, EBI-17762181; CC P11912; Q14318: FKBP8; NbExp=3; IntAct=EBI-7797864, EBI-724839; CC P11912; Q9BWH2: FUNDC2; NbExp=3; IntAct=EBI-7797864, EBI-714482; CC P11912; Q14802-3: FXYD3; NbExp=3; IntAct=EBI-7797864, EBI-12175685; CC P11912; Q8N3T1: GALNT15; NbExp=3; IntAct=EBI-7797864, EBI-3925203; CC P11912; Q8WWP7: GIMAP1; NbExp=3; IntAct=EBI-7797864, EBI-11991950; CC P11912; P08034: GJB1; NbExp=3; IntAct=EBI-7797864, EBI-17565645; CC P11912; O15529: GPR42; NbExp=3; IntAct=EBI-7797864, EBI-18076404; CC P11912; Q5VWC8: HACD4; NbExp=3; IntAct=EBI-7797864, EBI-18076069; CC P11912; P09601: HMOX1; NbExp=3; IntAct=EBI-7797864, EBI-2806151; CC P11912; P30519: HMOX2; NbExp=3; IntAct=EBI-7797864, EBI-712096; CC P11912; P46695: IER3; NbExp=3; IntAct=EBI-7797864, EBI-1748945; CC P11912; Q9Y5U4: INSIG2; NbExp=3; IntAct=EBI-7797864, EBI-8503746; CC P11912; P11215: ITGAM; NbExp=3; IntAct=EBI-7797864, EBI-2568251; CC P11912; Q8N5M9: JAGN1; NbExp=3; IntAct=EBI-7797864, EBI-10266796; CC P11912; P07942: LAMB1; NbExp=3; IntAct=EBI-7797864, EBI-949174; CC P11912; O95214: LEPROTL1; NbExp=3; IntAct=EBI-7797864, EBI-750776; CC P11912; Q8TAF8: LHFPL5; NbExp=3; IntAct=EBI-7797864, EBI-2820517; CC P11912; Q9UBY5: LPAR3; NbExp=3; IntAct=EBI-7797864, EBI-12033434; CC P11912; Q16873: LTC4S; NbExp=3; IntAct=EBI-7797864, EBI-12241118; CC P11912; Q13021: MALL; NbExp=3; IntAct=EBI-7797864, EBI-750078; CC P11912; Q9P0N8: MARCHF2; NbExp=3; IntAct=EBI-7797864, EBI-10317612; CC P11912; Q9GZY8-5: MFF; NbExp=3; IntAct=EBI-7797864, EBI-11956541; CC P11912; Q6NUT3-2: MFSD12; NbExp=3; IntAct=EBI-7797864, EBI-17295698; CC P11912; Q6N075: MFSD5; NbExp=3; IntAct=EBI-7797864, EBI-3920969; CC P11912; Q6ZSS7: MFSD6; NbExp=3; IntAct=EBI-7797864, EBI-2858252; CC P11912; A0A0C4DFN3: MGLL; NbExp=3; IntAct=EBI-7797864, EBI-12866138; CC P11912; Q8IY49-2: MMD2; NbExp=3; IntAct=EBI-7797864, EBI-13349813; CC P11912; O75425: MOSPD3; NbExp=3; IntAct=EBI-7797864, EBI-12179105; CC P11912; Q5J8X5: MS4A13; NbExp=3; IntAct=EBI-7797864, EBI-12070086; CC P11912; Q96S97: MYADM; NbExp=3; IntAct=EBI-7797864, EBI-13301517; CC P11912; A6NDP7: MYADML2; NbExp=3; IntAct=EBI-7797864, EBI-17641390; CC P11912; Q9UHE5: NAT8; NbExp=3; IntAct=EBI-7797864, EBI-2863634; CC P11912; Q99519: NEU1; NbExp=3; IntAct=EBI-7797864, EBI-721517; CC P11912; Q9NZG7: NINJ2; NbExp=3; IntAct=EBI-7797864, EBI-10317425; CC P11912; Q6P499: NIPAL3; NbExp=3; IntAct=EBI-7797864, EBI-10252783; CC P11912; Q16617: NKG7; NbExp=3; IntAct=EBI-7797864, EBI-3919611; CC P11912; Q8N912: NRAC; NbExp=3; IntAct=EBI-7797864, EBI-12051377; CC P11912; Q53FV1: ORMDL2; NbExp=3; IntAct=EBI-7797864, EBI-11075081; CC P11912; Q7RTS6: OTOP2; NbExp=3; IntAct=EBI-7797864, EBI-7642372; CC P11912; Q9UHJ9-5: PGAP2; NbExp=3; IntAct=EBI-7797864, EBI-12092917; CC P11912; Q99640-2: PKMYT1; NbExp=3; IntAct=EBI-7797864, EBI-12257782; CC P11912; Q04941: PLP2; NbExp=3; IntAct=EBI-7797864, EBI-608347; CC P11912; Q8IY26: PLPP6; NbExp=3; IntAct=EBI-7797864, EBI-11721828; CC P11912; Q96GM1: PLPPR2; NbExp=3; IntAct=EBI-7797864, EBI-12955265; CC P11912; P54315: PNLIPRP1; NbExp=3; IntAct=EBI-7797864, EBI-8652812; CC P11912; Q59EV6: PPGB; NbExp=3; IntAct=EBI-7797864, EBI-14210385; CC P11912; O60831: PRAF2; NbExp=3; IntAct=EBI-7797864, EBI-2506064; CC P11912; Q13635-3: PTCH1; NbExp=3; IntAct=EBI-7797864, EBI-14199621; CC P11912; Q96HR9-2: REEP6; NbExp=3; IntAct=EBI-7797864, EBI-14065960; CC P11912; P08100: RHO; NbExp=3; IntAct=EBI-7797864, EBI-1394177; CC P11912; Q5QGT7: RTP2; NbExp=3; IntAct=EBI-7797864, EBI-10244780; CC P11912; Q9NTJ5: SACM1L; NbExp=3; IntAct=EBI-7797864, EBI-3917235; CC P11912; O75396: SEC22B; NbExp=3; IntAct=EBI-7797864, EBI-1058865; CC P11912; Q9Y6X1: SERP1; NbExp=3; IntAct=EBI-7797864, EBI-10329948; CC P11912; P11686: SFTPC; NbExp=3; IntAct=EBI-7797864, EBI-10197617; CC P11912; Q9UKG4: SLC13A4; NbExp=6; IntAct=EBI-7797864, EBI-12808018; CC P11912; Q86YT5: SLC13A5; NbExp=3; IntAct=EBI-7797864, EBI-12002412; CC P11912; Q6ZSM3: SLC16A12; NbExp=3; IntAct=EBI-7797864, EBI-17460560; CC P11912; Q7RTY0: SLC16A13; NbExp=3; IntAct=EBI-7797864, EBI-12243266; CC P11912; Q9BRI3: SLC30A2; NbExp=3; IntAct=EBI-7797864, EBI-8644112; CC P11912; P78383: SLC35B1; NbExp=3; IntAct=EBI-7797864, EBI-12147661; CC P11912; Q969S0: SLC35B4; NbExp=3; IntAct=EBI-7797864, EBI-10281213; CC P11912; Q9H2H9: SLC38A1; NbExp=6; IntAct=EBI-7797864, EBI-9978441; CC P11912; Q9NP94: SLC39A2; NbExp=3; IntAct=EBI-7797864, EBI-12898013; CC P11912; Q9NUM3: SLC39A9; NbExp=3; IntAct=EBI-7797864, EBI-2823239; CC P11912; Q8IVJ1: SLC41A1; NbExp=3; IntAct=EBI-7797864, EBI-12266234; CC P11912; Q96JW4: SLC41A2; NbExp=3; IntAct=EBI-7797864, EBI-10290130; CC P11912; Q7Z3Q1-2: SLC46A3; NbExp=3; IntAct=EBI-7797864, EBI-18074862; CC P11912; Q8N2U9: SLC66A2; NbExp=3; IntAct=EBI-7797864, EBI-3907610; CC P11912; P48065: SLC6A12; NbExp=3; IntAct=EBI-7797864, EBI-3843589; CC P11912; P30825: SLC7A1; NbExp=3; IntAct=EBI-7797864, EBI-4289564; CC P11912; Q9NRQ5: SMCO4; NbExp=3; IntAct=EBI-7797864, EBI-8640191; CC P11912; Q9BZL3: SMIM3; NbExp=3; IntAct=EBI-7797864, EBI-741850; CC P11912; P0DN84: STRIT1; NbExp=3; IntAct=EBI-7797864, EBI-12200293; CC P11912; Q86Y82: STX12; NbExp=3; IntAct=EBI-7797864, EBI-2691717; CC P11912; Q13277: STX3; NbExp=3; IntAct=EBI-7797864, EBI-1394295; CC P11912; Q9UNK0: STX8; NbExp=3; IntAct=EBI-7797864, EBI-727240; CC P11912; P57105: SYNJ2BP; NbExp=3; IntAct=EBI-7797864, EBI-1049004; CC P11912; Q9NZ01: TECR; NbExp=3; IntAct=EBI-7797864, EBI-2877718; CC P11912; P07204: THBD; NbExp=3; IntAct=EBI-7797864, EBI-941422; CC P11912; Q96DZ7: TM4SF19; NbExp=3; IntAct=EBI-7797864, EBI-6448756; CC P11912; P48230: TM4SF4; NbExp=3; IntAct=EBI-7797864, EBI-8650934; CC P11912; P55061: TMBIM6; NbExp=3; IntAct=EBI-7797864, EBI-1045825; CC P11912; Q6UX40: TMEM107; NbExp=3; IntAct=EBI-7797864, EBI-12845616; CC P11912; P17152: TMEM11; NbExp=3; IntAct=EBI-7797864, EBI-723946; CC P11912; Q5BJH2-2: TMEM128; NbExp=3; IntAct=EBI-7797864, EBI-10694905; CC P11912; Q9NV12: TMEM140; NbExp=3; IntAct=EBI-7797864, EBI-2844246; CC P11912; Q9BVK8: TMEM147; NbExp=3; IntAct=EBI-7797864, EBI-348587; CC P11912; Q9NUH8: TMEM14B; NbExp=3; IntAct=EBI-7797864, EBI-8638294; CC P11912; Q96HP8: TMEM176A; NbExp=3; IntAct=EBI-7797864, EBI-2800645; CC P11912; Q14656: TMEM187; NbExp=3; IntAct=EBI-7797864, EBI-13046724; CC P11912; Q96HH6: TMEM19; NbExp=3; IntAct=EBI-7797864, EBI-741829; CC P11912; A2RU14: TMEM218; NbExp=3; IntAct=EBI-7797864, EBI-10173151; CC P11912; Q9H0R3: TMEM222; NbExp=3; IntAct=EBI-7797864, EBI-347385; CC P11912; Q8NBD8: TMEM229B; NbExp=3; IntAct=EBI-7797864, EBI-12195227; CC P11912; Q8WW34-2: TMEM239; NbExp=3; IntAct=EBI-7797864, EBI-11528917; CC P11912; Q9BU79: TMEM243; NbExp=3; IntAct=EBI-7797864, EBI-12887458; CC P11912; Q8TBM7: TMEM254; NbExp=3; IntAct=EBI-7797864, EBI-11956809; CC P11912; E9PQX1: TMEM262; NbExp=3; IntAct=EBI-7797864, EBI-17180389; CC P11912; Q69YG0: TMEM42; NbExp=3; IntAct=EBI-7797864, EBI-12038591; CC P11912; Q8N2M4: TMEM86A; NbExp=3; IntAct=EBI-7797864, EBI-12015604; CC P11912; Q8N661: TMEM86B; NbExp=3; IntAct=EBI-7797864, EBI-2548832; CC P11912; Q6ZT21: TMPPE; NbExp=3; IntAct=EBI-7797864, EBI-11724433; CC P11912; O14798: TNFRSF10C; NbExp=3; IntAct=EBI-7797864, EBI-717441; CC P11912; Q8N609: TRAM1L1; NbExp=3; IntAct=EBI-7797864, EBI-11996766; CC P11912; A0AVG3: TSNARE1; NbExp=3; IntAct=EBI-7797864, EBI-12003468; CC P11912; O60636: TSPAN2; NbExp=3; IntAct=EBI-7797864, EBI-3914288; CC P11912; Q5TGU0: TSPO2; NbExp=3; IntAct=EBI-7797864, EBI-12195249; CC P11912; A5PKU2: TUSC5; NbExp=3; IntAct=EBI-7797864, EBI-11988865; CC P11912; Q9Y385: UBE2J1; NbExp=3; IntAct=EBI-7797864, EBI-988826; CC P11912; Q9Y5Z9: UBIAD1; NbExp=3; IntAct=EBI-7797864, EBI-2819725; CC P11912; Q9H1C4: UNC93B1; NbExp=3; IntAct=EBI-7797864, EBI-4401271; CC P11912; Q15836: VAMP3; NbExp=3; IntAct=EBI-7797864, EBI-722343; CC P11912; Q9P0L0: VAPA; NbExp=3; IntAct=EBI-7797864, EBI-1059156; CC P11912; O95292: VAPB; NbExp=3; IntAct=EBI-7797864, EBI-1188298; CC P11912; Q9UEU0: VTI1B; NbExp=3; IntAct=EBI-7797864, EBI-723716; CC P11912; Q14508: WFDC2; NbExp=3; IntAct=EBI-7797864, EBI-723529; CC P11912; O76024: WFS1; NbExp=3; IntAct=EBI-7797864, EBI-720609; CC P11912; O95070: YIF1A; NbExp=3; IntAct=EBI-7797864, EBI-2799703; CC P11912; Q9BSR8: YIPF4; NbExp=3; IntAct=EBI-7797864, EBI-751253; CC P11912; Q96EC8: YIPF6; NbExp=3; IntAct=EBI-7797864, EBI-751210; CC P11912; Q96MV8: ZDHHC15; NbExp=3; IntAct=EBI-7797864, EBI-12837904; CC P11912; Q8N966: ZDHHC22; NbExp=3; IntAct=EBI-7797864, EBI-10268111; CC -!- SUBCELLULAR LOCATION: Cell membrane; Single-pass type I membrane CC protein. Note=Following antigen binding, the BCR has been shown to CC translocate from detergent-soluble regions of the cell membrane to CC lipid rafts although signal transduction through the complex can also CC occur outside lipid rafts. {ECO:0000250}. CC -!- ALTERNATIVE PRODUCTS: CC Event=Alternative splicing; Named isoforms=2; CC Name=1; Synonyms=Long; CC IsoId=P11912-1; Sequence=Displayed; CC Name=2; Synonyms=Short; CC IsoId=P11912-2; Sequence=VSP_002476; CC -!- TISSUE SPECIFICITY: B-cells. CC -!- DOMAIN: The transmembrane helices of CD79A and CD79B chains and two IgM CC heavy chains assembly in a four-helix bundle structure that appears to CC be conserved among different BCR isotypes. CC {ECO:0000269|PubMed:35981043}. CC -!- PTM: Phosphorylated on tyrosine, serine and threonine residues upon B- CC cell activation. Phosphorylation of tyrosine residues by Src-family CC kinases is an early and essential feature of the BCR signaling cascade. CC The phosphorylated tyrosines serve as docking sites for SH2-domain CC containing kinases, leading to their activation which in turn leads to CC phosphorylation of downstream targets. Phosphorylated by LYN. CC Phosphorylation of serine and threonine residues may prevent subsequent CC tyrosine phosphorylation. {ECO:0000269|PubMed:10748115, CC ECO:0000269|PubMed:10900006}. CC -!- PTM: Arginine methylation in the ITAM domain may interfere with the CC binding of SYK. It promotes signals leading to B-cell differentiation CC (By similarity). {ECO:0000250}. CC -!- DISEASE: Agammaglobulinemia 3, autosomal recessive (AGM3) [MIM:613501]: CC A primary immunodeficiency characterized by profoundly low or absent CC serum antibodies and low or absent circulating B-cells due to an early CC block of B-cell development. Affected individuals develop severe CC infections in the first years of life. {ECO:0000269|PubMed:10525050, CC ECO:0000269|PubMed:11920841}. Note=The disease is caused by variants CC affecting the gene represented in this entry. Two different mutations, CC one at the splice donor site of intron 2 and the other at the splice CC acceptor site for exon 3, have been identified. Both mutations give CC rise to a truncated protein. CC -!- WEB RESOURCE: Name=CD79Abase; Note=CD79A mutation db; CC URL="http://structure.bmc.lu.se/idbase/CD79Abase/"; 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; S46706; AAB23558.1; -; mRNA. DR EMBL; M80462; AAA59556.1; -; mRNA. DR EMBL; M74721; AAA60270.1; -; mRNA. DR EMBL; S75217; AAB20812.1; -; mRNA. DR EMBL; M86921; AAA59557.1; -; mRNA. DR EMBL; U05259; AAA20495.1; -; Genomic_DNA. DR EMBL; S79248; AAC60653.1; -; mRNA. DR EMBL; X83540; CAA58523.1; -; mRNA. DR EMBL; AK223371; BAD97091.1; -; mRNA. DR EMBL; X13451; CAA31802.1; ALT_SEQ; mRNA. DR CCDS; CCDS12589.1; -. [P11912-1] DR CCDS; CCDS46088.1; -. [P11912-2] DR PIR; I54539; A46477. DR PIR; S12504; S12504. DR RefSeq; NP_001774.1; NM_001783.3. [P11912-1] DR RefSeq; NP_067612.1; NM_021601.3. [P11912-2] DR PDB; 1CV9; NMR; -; A=184-195. DR PDB; 7WSO; EM; 3.03 A; A=33-169. DR PDB; 7WSP; EM; 4.09 A; A=33-169. DR PDB; 7XQ8; EM; 3.30 A; A=1-226. DR PDB; 7XT6; EM; 3.63 A; A=33-169. DR PDBsum; 1CV9; -. DR PDBsum; 7WSO; -. DR PDBsum; 7WSP; -. DR PDBsum; 7XQ8; -. DR PDBsum; 7XT6; -. DR AlphaFoldDB; P11912; -. DR BMRB; P11912; -. DR EMDB; EMD-32762; -. DR EMDB; EMD-32763; -. DR EMDB; EMD-33390; -. DR EMDB; EMD-33440; -. DR SMR; P11912; -. DR BioGRID; 107411; 241. DR ELM; P11912; -. DR IntAct; P11912; 198. DR MINT; P11912; -. DR STRING; 9606.ENSP00000221972; -. DR GlyConnect; 1028; 1 N-Linked glycan (1 site). DR GlyCosmos; P11912; 6 sites, 1 glycan. DR GlyGen; P11912; 9 sites, 1 N-linked glycan (1 site). DR iPTMnet; P11912; -. DR PhosphoSitePlus; P11912; -. DR BioMuta; CD79A; -. DR DMDM; 547896; -. DR CPTAC; CPTAC-1178; -. DR EPD; P11912; -. DR MassIVE; P11912; -. DR MaxQB; P11912; -. DR PaxDb; 9606-ENSP00000221972; -. DR PeptideAtlas; P11912; -. DR ProteomicsDB; 52811; -. [P11912-1] DR ProteomicsDB; 52812; -. [P11912-2] DR Antibodypedia; 2990; 2463 antibodies from 47 providers. DR DNASU; 973; -. DR Ensembl; ENST00000221972.8; ENSP00000221972.3; ENSG00000105369.10. [P11912-1] DR Ensembl; ENST00000444740.2; ENSP00000400605.1; ENSG00000105369.10. [P11912-2] DR GeneID; 973; -. DR KEGG; hsa:973; -. DR MANE-Select; ENST00000221972.8; ENSP00000221972.3; NM_001783.4; NP_001774.1. DR UCSC; uc002oru.4; human. [P11912-1] DR AGR; HGNC:1698; -. DR CTD; 973; -. DR DisGeNET; 973; -. DR GeneCards; CD79A; -. DR HGNC; HGNC:1698; CD79A. DR HPA; ENSG00000105369; Group enriched (intestine, lymphoid tissue). DR MalaCards; CD79A; -. DR MIM; 112205; gene. DR MIM; 613501; phenotype. DR neXtProt; NX_P11912; -. DR OpenTargets; ENSG00000105369; -. DR Orphanet; 33110; Autosomal agammaglobulinemia. DR PharmGKB; PA26237; -. DR VEuPathDB; HostDB:ENSG00000105369; -. DR eggNOG; ENOG502S1DI; Eukaryota. DR GeneTree; ENSGT00940000154363; -. DR HOGENOM; CLU_106774_0_0_1; -. DR InParanoid; P11912; -. DR OMA; RWQNEKF; -. DR OrthoDB; 5361630at2759; -. DR PhylomeDB; P11912; -. DR TreeFam; TF336032; -. DR PathwayCommons; P11912; -. DR Reactome; R-HSA-5690714; CD22 mediated BCR regulation. DR Reactome; R-HSA-9679191; Potential therapeutics for SARS. DR Reactome; R-HSA-983695; Antigen activates B Cell Receptor (BCR) leading to generation of second messengers. DR SignaLink; P11912; -. DR SIGNOR; P11912; -. DR BioGRID-ORCS; 973; 23 hits in 1151 CRISPR screens. DR EvolutionaryTrace; P11912; -. DR GeneWiki; CD79A; -. DR GenomeRNAi; 973; -. DR Pharos; P11912; Tbio. DR PRO; PR:P11912; -. DR Proteomes; UP000005640; Chromosome 19. DR RNAct; P11912; Protein. DR Bgee; ENSG00000105369; Expressed in spleen and 140 other cell types or tissues. DR ExpressionAtlas; P11912; baseline and differential. DR GO; GO:0019815; C:B cell receptor complex; ISS:UniProtKB. DR GO; GO:0009897; C:external side of plasma membrane; ISS:UniProtKB. DR GO; GO:0071755; C:IgM B cell receptor complex; IDA:UniProtKB. DR GO; GO:0045121; C:membrane raft; ISS:UniProtKB. DR GO; GO:0005771; C:multivesicular body; ISS:UniProtKB. DR GO; GO:0005886; C:plasma membrane; TAS:Reactome. DR GO; GO:0042802; F:identical protein binding; IDA:CAFA. DR GO; GO:0004888; F:transmembrane signaling receptor activity; IEA:Ensembl. DR GO; GO:0002250; P:adaptive immune response; IEA:UniProtKB-KW. DR GO; GO:0042113; P:B cell activation; ISS:UniProtKB. DR GO; GO:0030183; P:B cell differentiation; ISS:UniProtKB. DR GO; GO:0042100; P:B cell proliferation; ISS:UniProtKB. DR GO; GO:0050853; P:B cell receptor signaling pathway; ISS:UniProtKB. DR CDD; cd00096; Ig; 1. DR DisProt; DP01486; -. DR Gene3D; 2.60.40.10; Immunoglobulins; 1. DR InterPro; IPR039695; CD79a/CD79b. 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; IPR003598; Ig_sub2. DR InterPro; IPR013151; Immunoglobulin. 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; PF00047; ig; 1. DR Pfam; PF02189; ITAM; 1. DR SMART; SM00409; IG; 1. DR SMART; SM00408; IGc2; 1. DR SMART; SM00077; ITAM; 1. DR SUPFAM; SSF48726; Immunoglobulin; 1. DR PROSITE; PS50835; IG_LIKE; 1. DR PROSITE; PS51055; ITAM_1; 1. DR Genevisible; P11912; HS. PE 1: Evidence at protein level; KW 3D-structure; Adaptive immunity; Alternative splicing; Cell membrane; KW Direct protein sequencing; Disulfide bond; Glycoprotein; Immunity; KW Immunoglobulin domain; Membrane; Methylation; Phosphoprotein; KW Reference proteome; Signal; Transmembrane; Transmembrane helix. FT SIGNAL 1..32 FT /evidence="ECO:0000269|PubMed:7514267" FT CHAIN 33..226 FT /note="B-cell antigen receptor complex-associated protein FT alpha chain" FT /id="PRO_0000014558" FT TOPO_DOM 33..143 FT /note="Extracellular" FT /evidence="ECO:0000255" FT TRANSMEM 144..165 FT /note="Helical" FT /evidence="ECO:0000255" FT TOPO_DOM 166..226 FT /note="Cytoplasmic" FT /evidence="ECO:0000255" FT DOMAIN 33..116 FT /note="Ig-like C2-type" FT DOMAIN 177..205 FT /note="ITAM" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00379" FT SITE 210 FT /note="Required for binding to BLNK" FT /evidence="ECO:0000250" FT MOD_RES 188 FT /note="Phosphotyrosine; by SRC-type Tyr-kinases" FT /evidence="ECO:0000250|UniProtKB:P11911, FT ECO:0000255|PROSITE-ProRule:PRU00379" FT MOD_RES 199 FT /note="Phosphotyrosine; by SRC-type Tyr-kinases" FT /evidence="ECO:0000250|UniProtKB:P11911, FT ECO:0000255|PROSITE-ProRule:PRU00379" FT MOD_RES 204 FT /note="Asymmetric dimethylarginine; by PRMT1" FT /evidence="ECO:0000250|UniProtKB:P11911" FT MOD_RES 210 FT /note="Phosphotyrosine; by Tyr-kinases" FT /evidence="ECO:0000250|UniProtKB:P11911, FT ECO:0000255|PROSITE-ProRule:PRU00379" FT CARBOHYD 57 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255, ECO:0000269|PubMed:35981043, FT ECO:0007744|PDB:7XQ8" FT CARBOHYD 63 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255, ECO:0000269|PubMed:35981043, FT ECO:0007744|PDB:7XQ8" FT CARBOHYD 73 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255, ECO:0000269|PubMed:35981043, FT ECO:0007744|PDB:7XQ8" FT CARBOHYD 88 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255, ECO:0000269|PubMed:35981043, FT ECO:0007744|PDB:7XQ8" FT CARBOHYD 97 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255, ECO:0000269|PubMed:35981043, FT ECO:0007744|PDB:7XQ8" FT CARBOHYD 112 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255, ECO:0000269|PubMed:35981043, FT ECO:0007744|PDB:7XQ8" FT DISULFID 54..106 FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114, FT ECO:0000269|PubMed:35981043, ECO:0007744|PDB:7XQ8" FT DISULFID 119 FT /note="Interchain (with C-136 in beta chain)" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114, FT ECO:0000269|PubMed:35981043, ECO:0007744|PDB:7XQ8" FT VAR_SEQ 89..127 FT /note="GTLIIQNVNKSHGGIYVCRVQEGNESYQQSCGTYLRVRQ -> E (in FT isoform 2)" FT /evidence="ECO:0000303|PubMed:7643857, ECO:0000303|Ref.9" FT /id="VSP_002476" FT MUTAGEN 152 FT /note="L->W: Blocks IgMBCR assembly." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 156 FT /note="A->W: Blocks IgMBCR assembly." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 197 FT /note="S->A: Increased phosphorylation of Y-188; when FT associated with A-203 and V-209." FT /evidence="ECO:0000269|PubMed:10900006" FT MUTAGEN 203 FT /note="S->A: Increased phosphorylation of Y-188; when FT associated with A-197 and V-209." FT /evidence="ECO:0000269|PubMed:10900006" FT MUTAGEN 209 FT /note="T->V: Increased phosphorylation of Y-188; when FT associated with A-197 and A-203." FT /evidence="ECO:0000269|PubMed:10900006" FT CONFLICT 47 FT /note="G -> V (in Ref. 10; BAD97091)" FT /evidence="ECO:0000305" FT CONFLICT 69 FT /note="V -> I (in Ref. 3; AAA60270)" FT /evidence="ECO:0000305" FT CONFLICT 189 FT /note="E -> G (in Ref. 10; BAD97091)" FT /evidence="ECO:0000305" FT HELIX 34..36 FT /evidence="ECO:0007829|PDB:7WSO" FT STRAND 40..44 FT /evidence="ECO:0007829|PDB:7WSO" FT STRAND 50..52 FT /evidence="ECO:0007829|PDB:7WSO" FT STRAND 63..69 FT /evidence="ECO:0007829|PDB:7WSO" FT STRAND 71..74 FT /evidence="ECO:0007829|PDB:7WSO" FT STRAND 79..83 FT /evidence="ECO:0007829|PDB:7WSO" FT HELIX 87..89 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 91..93 FT /evidence="ECO:0007829|PDB:7WSO" FT HELIX 98..100 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 102..109 FT /evidence="ECO:0007829|PDB:7WSO" FT STRAND 122..125 FT /evidence="ECO:0007829|PDB:7WSO" FT STRAND 134..136 FT /evidence="ECO:0007829|PDB:7WSO" FT STRAND 138..141 FT /evidence="ECO:0007829|PDB:7WSO" FT HELIX 142..167 FT /evidence="ECO:0007829|PDB:7WSO" SQ SEQUENCE 226 AA; 25038 MW; 6E5B837409969292 CRC64; MPGGPGVLQA LPATIFLLFL LSAVYLGPGC QALWMHKVPA SLMVSLGEDA HFQCPHNSSN NANVTWWRVL HGNYTWPPEF LGPGEDPNGT LIIQNVNKSH GGIYVCRVQE GNESYQQSCG TYLRVRQPPP RPFLDMGEGT KNRIITAEGI ILLFCAVVPG TLLLFRKRWQ NEKLGLDAGD EYEDENLYEG LNLDDCSMYE DISRGLQGTY QDVGSLNIGD VQLEKP //