CD79A_MOUSE
ID CD79A_MOUSE Reviewed; 220 AA.
AC P11911; Q6GTY0;
DT 01-OCT-1989, integrated into UniProtKB/Swiss-Prot.
DT 24-JUL-2007, sequence version 2.
DT 03-AUG-2022, entry version 194.
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, Mb-1;
OS Mus musculus (Mouse).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae;
OC Murinae; Mus; Mus.
OX NCBI_TaxID=10090;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC STRAIN=C57BL/6 X DBA/2J;
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 [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=BALB/cJ; TISSUE=Liver;
RX PubMed=2358676;
RA Kashiwamura S., Koyama T., Matsuo T., Steinmetz M., Kimoto M.,
RA Sakaguchi N.;
RT "Structure of the murine mb-1 gene encoding a putative sIgM-associated
RT molecule.";
RL J. Immunol. 145:337-343(1990).
RN [3]
RP NUCLEOTIDE SEQUENCE.
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 [LARGE SCALE MRNA].
RC STRAIN=C57BL/6J; TISSUE=Mammary gland;
RX PubMed=15489334; DOI=10.1101/gr.2596504;
RG The MGC Project Team;
RT "The status, quality, and expansion of the NIH full-length cDNA project:
RT the Mammalian Gene Collection (MGC).";
RL Genome Res. 14:2121-2127(2004).
RN [5]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-15.
RX PubMed=1922076; DOI=10.1128/mcb.11.11.5756-5766.1991;
RA Travis A., Hagman J., Grosschedl R.;
RT "Heterogeneously initiated transcription from the pre-B- and B-cell-
RT specific mb-1 promoter: analysis of the requirement for upstream factor-
RT binding sites and initiation site sequences.";
RL Mol. Cell. Biol. 11:5756-5766(1991).
RN [6]
RP PROTEIN SEQUENCE OF 29-38.
RX PubMed=2269334; DOI=10.1002/eji.1830201239;
RA Hombach J., Lottspeich F., Reth M.;
RT "Identification of the genes encoding the IgM-alpha and Ig-beta components
RT of the IgM antigen receptor complex by amino-terminal sequencing.";
RL Eur. J. Immunol. 20:2795-2799(1990).
RN [7]
RP PROTEIN SEQUENCE OF 29-38.
RX PubMed=2023945; DOI=10.1073/pnas.88.9.3982;
RA Campbell K.S., Hager E.J., Friedrich R.J., Cambier J.C.;
RT "IgM antigen receptor complex contains phosphoprotein products of B29 and
RT mb-1 genes.";
RL Proc. Natl. Acad. Sci. U.S.A. 88:3982-3986(1991).
RN [8]
RP INTERACTION WITH BLK.
RX PubMed=1506682;
RA Lin J., Justement L.B.;
RT "The MB-1/B29 heterodimer couples the B cell antigen receptor to multiple
RT src family protein tyrosine kinases.";
RL J. Immunol. 149:1548-1555(1992).
RN [9]
RP INTERACTION WITH LYN, AND PHOSPHORYLATION.
RX PubMed=15335855; DOI=10.1016/0960-9822(93)90062-s;
RA Law D.A., Chan V.W., Datta S.K., DeFranco A.L.;
RT "B-cell antigen receptor motifs have redundant signalling capabilities and
RT bind the tyrosine kinases PTK72, Lyn and Fyn.";
RL Curr. Biol. 3:645-657(1993).
RN [10]
RP PHOSPHORYLATION AT TYR-182, AND MUTAGENESIS OF TYR-176; TYR-182 AND
RP TYR-193.
RX PubMed=8306975; DOI=10.1002/j.1460-2075.1994.tb06237.x;
RA Flaswinkel H., Reth M.;
RT "Dual role of the tyrosine activation motif of the Ig-alpha protein during
RT signal transduction via the B cell antigen receptor.";
RL EMBO J. 13:83-89(1994).
RN [11]
RP INTERACTION WITH FYN AND LYN.
RX PubMed=8168489; DOI=10.1002/j.1460-2075.1994.tb06460.x;
RA Clark M.R., Johnson S.A., Cambier J.C.;
RT "Analysis of Ig-alpha-tyrosine kinase interaction reveals two levels of
RT binding specificity and tyrosine phosphorylated Ig-alpha stimulation of Fyn
RT activity.";
RL EMBO J. 13:1911-1919(1994).
RN [12]
RP FUNCTION.
RX PubMed=8175787; DOI=10.1016/s0021-9258(17)36863-1;
RA Taddie J.A., Hurley T.R., Hardwick B.S., Sefton B.M.;
RT "Activation of B- and T-cells by the cytoplasmic domains of the B-cell
RT antigen receptor proteins Ig-alpha and Ig-beta.";
RL J. Biol. Chem. 269:13529-13535(1994).
RN [13]
RP INTERACTION WITH SYK.
RX PubMed=7538118; DOI=10.1074/jbc.270.19.11590;
RA Rowley R.B., Burkhardt A.L., Chao H.-G., Matsueda G.R., Bolen J.B.;
RT "Syk protein-tyrosine kinase is regulated by tyrosine-phosphorylated Ig
RT alpha/Ig beta immunoreceptor tyrosine activation motif binding and
RT autophosphorylation.";
RL J. Biol. Chem. 270:11590-11594(1995).
RN [14]
RP INTERACTION WITH BLK, AND PHOSPHORYLATION AT TYR-182 AND TYR-193.
RX PubMed=7592958; DOI=10.1074/jbc.270.45.27072;
RA Saouaf S.J., Kut S.A., Fargnoli J., Rowley R.B., Bolen J.B., Mahajan S.;
RT "Reconstitution of the B cell antigen receptor signaling components in COS
RT cells.";
RL J. Biol. Chem. 270:27072-27078(1995).
RN [15]
RP FUNCTION, AND MUTAGENESIS OF TYR-182 AND TYR-193.
RX PubMed=9469435;
RA Cassard S., Salamero J., Hanau D., Spehner D., Davoust J., Fridman W.H.,
RA Bonnerot C.;
RT "A tyrosine-based signal present in Ig alpha mediates B cell receptor
RT constitutive internalization.";
RL J. Immunol. 160:1767-1773(1998).
RN [16]
RP FUNCTION.
RX PubMed=10591178; DOI=10.1016/s1074-7613(00)80128-4;
RA Torres R.M., Hafen K.;
RT "A negative regulatory role for Ig-alpha during B cell development.";
RL Immunity 11:527-536(1999).
RN [17]
RP SUBCELLULAR LOCATION.
RX PubMed=10587346; DOI=10.1084/jem.190.11.1549;
RA Cheng P.C., Dykstra M.L., Mitchell R.N., Pierce S.K.;
RT "A role for lipid rafts in B cell antigen receptor signaling and antigen
RT targeting.";
RL J. Exp. Med. 190:1549-1560(1999).
RN [18]
RP FUNCTION.
RX PubMed=10352267;
RA Siemasko K., Eisfelder B.J., Stebbins C., Kabak S., Sant A.J., Song W.,
RA Clark M.R.;
RT "Ig alpha and Ig beta are required for efficient trafficking to late
RT endosomes and to enhance antigen presentation.";
RL J. Immunol. 162:6518-6525(1999).
RN [19]
RP INTERACTION WITH BLNK, PHOSPHORYLATION AT TYR-204, AND MUTAGENESIS OF
RP TYR-204.
RX PubMed=11449366;
RX DOI=10.1002/1521-4141(200107)31:7<2126::aid-immu2126>3.0.co;2-o;
RA Engels N., Wollscheid B., Wienands J.;
RT "Association of SLP-65/BLNK with the B cell antigen receptor through a non-
RT ITAM tyrosine of Ig-alpha.";
RL Eur. J. Immunol. 31:2126-2134(2001).
RN [20]
RP FUNCTION, AND MUTAGENESIS OF TYR-182 AND TYR-193.
RX PubMed=11514602; DOI=10.1084/jem.194.4.455;
RA Kraus M., Pao L.I., Reichlin A., Hu Y., Canono B., Cambier J.C.,
RA Nussenzweig M.C., Rajewsky K.;
RT "Interference with immunoglobulin (Ig)alpha immunoreceptor tyrosine-based
RT activation motif (ITAM) phosphorylation modulates or blocks B cell
RT development, depending on the availability of an Igbeta cytoplasmic tail.";
RL J. Exp. Med. 194:455-469(2001).
RN [21]
RP SUBCELLULAR LOCATION.
RX PubMed=11238609; DOI=10.4049/jimmunol.166.6.3693;
RA Cheng P.C., Brown B.K., Song W., Pierce S.K.;
RT "Translocation of the B cell antigen receptor into lipid rafts reveals a
RT novel step in signaling.";
RL J. Immunol. 166:3693-3701(2001).
RN [22]
RP FUNCTION.
RX PubMed=12356683; DOI=10.1093/intimm/14.10.1179;
RA Li C., Siemasko K., Clark M.R., Song W.;
RT "Cooperative interaction of Ig(alpha) and Ig(beta) of the BCR regulates the
RT kinetics and specificity of antigen targeting.";
RL Int. Immunol. 14:1179-1191(2002).
RN [23]
RP FUNCTION, INTERACTION WITH BLNK, AND MUTAGENESIS OF TYR-176 AND TYR-204.
RX PubMed=11859098; DOI=10.4049/jimmunol.168.5.2127;
RA Siemasko K., Skaggs B.J., Kabak S., Williamson E., Brown B.K., Song W.,
RA Clark M.R.;
RT "Receptor-facilitated antigen presentation requires the recruitment of B
RT cell linker protein to Igalpha.";
RL J. Immunol. 168:2127-2138(2002).
RN [24]
RP FUNCTION, AND DISRUPTION PHENOTYPE.
RX PubMed=12097390; DOI=10.4049/jimmunol.169.2.865;
RA Pelanda R., Braun U., Hobeika E., Nussenzweig M.C., Reth M.;
RT "B cell progenitors are arrested in maturation but have intact VDJ
RT recombination in the absence of Ig-alpha and Ig-beta.";
RL J. Immunol. 169:865-872(2002).
RN [25]
RP INTERACTION WITH BLNK, AND MUTAGENESIS OF TYR-176 AND TYR-204.
RX PubMed=11909947; DOI=10.1128/mcb.22.8.2524-2535.2002;
RA Kabak S., Skaggs B.J., Gold M.R., Affolter M., West K.L., Foster M.S.,
RA Siemasko K., Chan A.C., Aebersold R., Clark M.R.;
RT "The direct recruitment of BLNK to immunoglobulin alpha couples the B-cell
RT antigen receptor to distal signaling pathways.";
RL Mol. Cell. Biol. 22:2524-2535(2002).
RN [26]
RP FUNCTION, AND SUBCELLULAR LOCATION.
RX PubMed=15661879; DOI=10.4049/jimmunol.174.3.1245;
RA Fuentes-Panana E.M., Bannish G., van der Voort D., King L.B., Monroe J.G.;
RT "Ig alpha/Ig beta complexes generate signals for B cell development
RT independent of selective plasma membrane compartmentalization.";
RL J. Immunol. 174:1245-1252(2005).
RN [27]
RP FUNCTION, AND MUTAGENESIS OF TYR-176 AND TYR-204.
RX PubMed=16860757; DOI=10.1016/j.immuni.2006.04.014;
RA Patterson H.C.K., Kraus M., Kim Y.-M., Ploegh H., Rajewsky K.;
RT "The B cell receptor promotes B cell activation and proliferation through a
RT non-ITAM tyrosine in the Igalpha cytoplasmic domain.";
RL Immunity 25:55-65(2006).
RN [28]
RP FUNCTION, AND MUTAGENESIS OF TYR-176; TYR-182; TYR-193 AND TYR-204.
RX PubMed=17163454; DOI=10.1002/eji.200636667;
RA Storch B., Meixlsperger S., Jumaa H.;
RT "The Ig-alpha ITAM is required for efficient differentiation but not
RT proliferation of pre-B cells.";
RL Eur. J. Immunol. 37:252-260(2007).
RN [29]
RP IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
RC TISSUE=Spleen;
RX PubMed=21183079; DOI=10.1016/j.cell.2010.12.001;
RA Huttlin E.L., Jedrychowski M.P., Elias J.E., Goswami T., Rad R.,
RA Beausoleil S.A., Villen J., Haas W., Sowa M.E., Gygi S.P.;
RT "A tissue-specific atlas of mouse protein phosphorylation and expression.";
RL Cell 143:1174-1189(2010).
RN [30]
RP METHYLATION AT ARG-198 BY PRMT1, AND MUTAGENESIS OF ARG-198.
RX PubMed=20231378; DOI=10.1084/jem.20091303;
RA Infantino S., Benz B., Waldmann T., Jung M., Schneider R., Reth M.;
RT "Arginine methylation of the B cell antigen receptor promotes
RT differentiation.";
RL J. Exp. Med. 207:711-719(2010).
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:10352267, ECO:0000269|PubMed:10591178,
CC ECO:0000269|PubMed:11514602, ECO:0000269|PubMed:11859098,
CC ECO:0000269|PubMed:12097390, ECO:0000269|PubMed:12356683,
CC ECO:0000269|PubMed:15661879, ECO:0000269|PubMed:16860757,
CC ECO:0000269|PubMed:17163454, ECO:0000269|PubMed:8175787,
CC ECO:0000269|PubMed:9469435}.
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-204, 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. {ECO:0000269|PubMed:11449366,
CC ECO:0000269|PubMed:11859098, ECO:0000269|PubMed:11909947,
CC ECO:0000269|PubMed:1506682, ECO:0000269|PubMed:15335855,
CC ECO:0000269|PubMed:7538118, ECO:0000269|PubMed:7592958,
CC ECO:0000269|PubMed:8168489}.
CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000269|PubMed:10587346,
CC ECO:0000269|PubMed:11238609, ECO:0000269|PubMed:15661879}; Single-pass
CC type I membrane protein {ECO:0000269|PubMed:10587346,
CC ECO:0000269|PubMed:11238609, ECO:0000269|PubMed:15661879}.
CC Note=Following antigen binding, the BCR has been shown to translocate
CC from detergent-soluble regions of the cell membrane to lipid rafts
CC although signal transduction through the complex can also occur outside
CC lipid rafts.
CC -!- TISSUE SPECIFICITY: B-cells.
CC -!- PTM: Phosphorylated on tyrosine, serine and threonine residues upon B-
CC cell activation. Phosphorylation of tyrosine residues by Src-family
CC kinases, including LYN, is an early and essential feature of the BCR
CC signaling cascade. The phosphorylated tyrosines serve as docking sites
CC for SH2-domain containing kinases, leading to their activation which in
CC turn leads to phosphorylation of downstream targets. Phosphorylation of
CC serine and threonine residues may prevent subsequent tyrosine
CC phosphorylation. {ECO:0000269|PubMed:11449366,
CC ECO:0000269|PubMed:15335855, ECO:0000269|PubMed:7592958,
CC ECO:0000269|PubMed:8306975}.
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 {ECO:0000269|PubMed:20231378}.
CC -!- DISRUPTION PHENOTYPE: Mice display impaired B-cell development which
CC does not progress pass the progenitor stage.
CC {ECO:0000269|PubMed:12097390}.
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DR EMBL; X13450; CAA31801.1; -; mRNA.
DR EMBL; M31773; AAA39494.1; -; Genomic_DNA.
DR EMBL; BC027633; AAH27633.1; -; mRNA.
DR EMBL; S59359; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR CCDS; CCDS20967.1; -.
DR PIR; A43540; A43540.
DR RefSeq; NP_031681.2; NM_007655.3.
DR AlphaFoldDB; P11911; -.
DR BioGRID; 198611; 4.
DR DIP; DIP-61170N; -.
DR ELM; P11911; -.
DR IntAct; P11911; 2.
DR STRING; 10090.ENSMUSP00000003469; -.
DR GlyGen; P11911; 2 sites.
DR iPTMnet; P11911; -.
DR PhosphoSitePlus; P11911; -.
DR EPD; P11911; -.
DR MaxQB; P11911; -.
DR PaxDb; P11911; -.
DR PRIDE; P11911; -.
DR ProteomicsDB; 281271; -.
DR Antibodypedia; 2990; 2240 antibodies from 47 providers.
DR DNASU; 12518; -.
DR Ensembl; ENSMUST00000003469; ENSMUSP00000003469; ENSMUSG00000003379.
DR GeneID; 12518; -.
DR KEGG; mmu:12518; -.
DR UCSC; uc009fqt.1; mouse.
DR CTD; 973; -.
DR MGI; MGI:101774; Cd79a.
DR VEuPathDB; HostDB:ENSMUSG00000003379; -.
DR eggNOG; ENOG502S1DI; Eukaryota.
DR GeneTree; ENSGT00940000154363; -.
DR HOGENOM; CLU_106774_0_0_1; -.
DR InParanoid; P11911; -.
DR OMA; RWQNEKF; -.
DR OrthoDB; 1165385at2759; -.
DR PhylomeDB; P11911; -.
DR TreeFam; TF336032; -.
DR Reactome; R-MMU-5690714; CD22 mediated BCR regulation.
DR Reactome; R-MMU-983695; Antigen activates B Cell Receptor (BCR) leading to generation of second messengers.
DR BioGRID-ORCS; 12518; 3 hits in 73 CRISPR screens.
DR ChiTaRS; Cd79a; mouse.
DR PRO; PR:P11911; -.
DR Proteomes; UP000000589; Chromosome 7.
DR RNAct; P11911; protein.
DR Bgee; ENSMUSG00000003379; Expressed in spleen and 46 other tissues.
DR Genevisible; P11911; MM.
DR GO; GO:0019815; C:B cell receptor complex; IDA:MGI.
DR GO; GO:0009897; C:external side of plasma membrane; IDA:MGI.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0045121; C:membrane raft; IDA:UniProtKB.
DR GO; GO:0005771; C:multivesicular body; IDA:MGI.
DR GO; GO:0005886; C:plasma membrane; TAS:Reactome.
DR GO; GO:0042802; F:identical protein binding; ISO:MGI.
DR GO; GO:0004888; F:transmembrane signaling receptor activity; IEA:InterPro.
DR GO; GO:0002250; P:adaptive immune response; IEA:UniProtKB-KW.
DR GO; GO:0042113; P:B cell activation; IMP:UniProtKB.
DR GO; GO:0030183; P:B cell differentiation; IMP:UniProtKB.
DR GO; GO:0042100; P:B cell proliferation; IMP:UniProtKB.
DR GO; GO:0050853; P:B cell receptor signaling pathway; IDA:MGI.
DR Gene3D; 2.60.40.10; -; 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; IPR013151; Immunoglobulin.
DR InterPro; IPR003110; Phos_immunorcpt_sig_ITAM.
DR PANTHER; PTHR14334; PTHR14334; 1.
DR Pfam; PF00047; ig; 1.
DR Pfam; PF02189; ITAM; 1.
DR SMART; SM00409; IG; 1.
DR SMART; SM00077; ITAM; 1.
DR SUPFAM; SSF48726; SSF48726; 1.
DR PROSITE; PS50835; IG_LIKE; 1.
DR PROSITE; PS51055; ITAM_1; 1.
PE 1: Evidence at protein level;
KW Adaptive immunity; Cell membrane; Direct protein sequencing;
KW Disulfide bond; Glycoprotein; Immunity; Immunoglobulin domain; Membrane;
KW Methylation; Phosphoprotein; Reference proteome; Signal; Transmembrane;
KW Transmembrane helix.
FT SIGNAL 1..28
FT /evidence="ECO:0000269|PubMed:2023945,
FT ECO:0000269|PubMed:2269334"
FT CHAIN 29..220
FT /note="B-cell antigen receptor complex-associated protein
FT alpha chain"
FT /id="PRO_0000014559"
FT TOPO_DOM 29..137
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT TRANSMEM 138..159
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 160..220
FT /note="Cytoplasmic"
FT /evidence="ECO:0000255"
FT DOMAIN 29..117
FT /note="Ig-like C2-type"
FT DOMAIN 171..199
FT /note="ITAM"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00379"
FT SITE 204
FT /note="Required for binding to BLNK"
FT MOD_RES 182
FT /note="Phosphotyrosine; by SRC-type Tyr-kinases"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00379,
FT ECO:0000269|PubMed:7592958, ECO:0000269|PubMed:8306975"
FT MOD_RES 193
FT /note="Phosphotyrosine; by SRC-type Tyr-kinases"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00379,
FT ECO:0000269|PubMed:7592958"
FT MOD_RES 198
FT /note="Asymmetric dimethylarginine; by PRMT1"
FT /evidence="ECO:0000269|PubMed:20231378"
FT MOD_RES 204
FT /note="Phosphotyrosine; by Tyr-kinases"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00379,
FT ECO:0000269|PubMed:11449366"
FT CARBOHYD 58
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 68
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT DISULFID 50..101
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114"
FT DISULFID 113
FT /note="Interchain (with C-135 in beta chain)"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114"
FT MUTAGEN 176
FT /note="Y->F: Increases tyrosine phosphorylation. Inhibits
FT phosphorylation of BLNK. Impaired antigen presentation;
FT when associated with F-204."
FT /evidence="ECO:0000269|PubMed:11859098,
FT ECO:0000269|PubMed:11909947, ECO:0000269|PubMed:16860757,
FT ECO:0000269|PubMed:17163454, ECO:0000269|PubMed:8306975"
FT MUTAGEN 182
FT /note="Y->F: Strongly reduces tyrosine phosphorylation and
FT pre-B-cell differentiation; when associated with F-193.
FT Abolishes constitutive internalization of BCR."
FT /evidence="ECO:0000269|PubMed:11514602,
FT ECO:0000269|PubMed:17163454, ECO:0000269|PubMed:8306975,
FT ECO:0000269|PubMed:9469435"
FT MUTAGEN 193
FT /note="Y->F: Strongly reduces tyrosine phosphorylation and
FT pre-B-cell differentiation; when associated with F-182. No
FT effect on constitutive internalization of BCR."
FT /evidence="ECO:0000269|PubMed:11514602,
FT ECO:0000269|PubMed:17163454, ECO:0000269|PubMed:8306975,
FT ECO:0000269|PubMed:9469435"
FT MUTAGEN 198
FT /note="R->K: Associates more strongly with SYK. Increases
FT calcium response upon BCR ligation."
FT /evidence="ECO:0000269|PubMed:20231378"
FT MUTAGEN 204
FT /note="Y->F: Has little effect on tyrosine phosphorylation.
FT Reduces pre-B-cell differentiation. Abolishes binding to
FT BLNK. Inhibits phosphorylation of BLNK. No effect on cap
FT formation or BCR internalization. Impaired antigen
FT presentation; when associated with F-176."
FT /evidence="ECO:0000269|PubMed:11449366,
FT ECO:0000269|PubMed:11859098, ECO:0000269|PubMed:11909947,
FT ECO:0000269|PubMed:16860757, ECO:0000269|PubMed:17163454"
FT CONFLICT 95..100
FT /note="HRGLYW -> TGACTG (in Ref. 1; CAA31801 and 2;
FT AAA39494)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 220 AA; 24583 MW; A4C648C2BE6D3E38 CRC64;
MPGGLEALRA LPLLLFLSYA CLGPGCQALR VEGGPPSLTV NLGEEARLTC ENNGRNPNIT
WWFSLQSNIT WPPVPLGPGQ GTTGQLFFPE VNKNHRGLYW CQVIENNILK RSCGTYLRVR
NPVPRPFLDM GEGTKNRIIT AEGIILLFCA VVPGTLLLFR KRWQNEKFGV DMPDDYEDEN
LYEGLNLDDC SMYEDISRGL QGTYQDVGNL HIGDAQLEKP
