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Protein

B-cell antigen receptor complex-associated protein alpha chain

Gene

Cd79a

Organism
Mus musculus (Mouse)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Required in cooperation with CD79B for initiation of the signal transduction cascade activated by binding of antigen to the B-cell antigen receptor complex (BCR) which leads to internalization of the complex, trafficking to late endosomes and antigen presentation. Also required for BCR surface expression and for efficient differentiation of pro- and pre-B-cells. Stimulates SYK autophosphorylation and activation. Binds to BLNK, bringing BLNK into proximity with SYK and allowing SYK to phosphorylate BLNK. Also interacts with and increases activity of some Src-family tyrosine kinases. Represses BCR signaling during development of immature B-cells.11 Publications

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei204Required for binding to BLNK1

GO - Molecular functioni

GO - Biological processi

  • adaptive immune response Source: UniProtKB-KW
  • B cell activation Source: UniProtKB
  • B cell differentiation Source: UniProtKB
  • B cell proliferation Source: UniProtKB
  • B cell receptor signaling pathway Source: MGI
  • protein homotetramerization Source: MGI

Keywordsi

Biological processAdaptive immunity, Immunity

Enzyme and pathway databases

ReactomeiR-MMU-983695. Antigen activates B Cell Receptor (BCR) leading to generation of second messengers.

Names & Taxonomyi

Protein namesi
Recommended name:
B-cell antigen receptor complex-associated protein alpha chain
Alternative name(s):
Ig-alpha
MB-1 membrane glycoprotein
Membrane-bound immunoglobulin-associated protein
Surface IgM-associated protein
CD_antigen: CD79a
Gene namesi
Name:Cd79a
Synonyms:Iga, Mb-1
OrganismiMus musculus (Mouse)
Taxonomic identifieri10090 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaMyomorphaMuroideaMuridaeMurinaeMusMus
Proteomesi
  • UP000000589 Componenti: Chromosome 7

Organism-specific databases

MGIiMGI:101774. Cd79a.

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini29 – 137ExtracellularSequence analysisAdd BLAST109
Transmembranei138 – 159HelicalSequence analysisAdd BLAST22
Topological domaini160 – 220CytoplasmicSequence analysisAdd BLAST61

Keywords - Cellular componenti

Cell membrane, Membrane

Pathology & Biotechi

Disruption phenotypei

Mice display impaired B-cell development which does not progress pass the progenitor stage.1 Publication

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi176Y → F: Increases tyrosine phosphorylation. Inhibits phosphorylation of BLNK. Impaired antigen presentation; when associated with F-204. 5 Publications1
Mutagenesisi182Y → F: Strongly reduces tyrosine phosphorylation and pre-B-cell differentiation; when associated with F-193. Abolishes constitutive internalization of BCR. 4 Publications1
Mutagenesisi193Y → F: Strongly reduces tyrosine phosphorylation and pre-B-cell differentiation; when associated with F-182. No effect on constitutive internalization of BCR. 4 Publications1
Mutagenesisi198R → K: Associates more strongly with SYK. Increases calcium response upon BCR ligation. 1 Publication1
Mutagenesisi204Y → F: Has little effect on tyrosine phosphorylation. Reduces pre-B-cell differentiation. Abolishes binding to BLNK. Inhibits phosphorylation of BLNK. No effect on cap formation or BCR internalization. Impaired antigen presentation; when associated with F-176. 5 Publications1

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 282 PublicationsAdd BLAST28
ChainiPRO_000001455929 – 220B-cell antigen receptor complex-associated protein alpha chainAdd BLAST192

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi50 ↔ 101PROSITE-ProRule annotation
Glycosylationi58N-linked (GlcNAc...) asparagineSequence analysis1
Glycosylationi68N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi113Interchain (with C-135 in beta chain)PROSITE-ProRule annotation
Modified residuei182Phosphotyrosine; by SRC-type Tyr-kinasesPROSITE-ProRule annotation2 Publications1
Modified residuei193Phosphotyrosine; by SRC-type Tyr-kinasesPROSITE-ProRule annotation1 Publication1
Modified residuei198Asymmetric dimethylarginine; by PRMT11 Publication1
Modified residuei204Phosphotyrosine; by Tyr-kinasesPROSITE-ProRule annotation1 Publication1

Post-translational modificationi

Phosphorylated on tyrosine, serine and threonine residues upon B-cell activation. Phosphorylation of tyrosine residues by Src-family kinases, including LYN, is an early and essential feature of the BCR signaling cascade. The phosphorylated tyrosines serve as docking sites for SH2-domain containing kinases, leading to their activation which in turn leads to phosphorylation of downstream targets. Phosphorylation of serine and threonine residues may prevent subsequent tyrosine phosphorylation.4 Publications
Arginine methylation in the ITAM domain may interfere with the binding of SYK. It promotes signals leading to B-cell differentiation.1 Publication

Keywords - PTMi

Disulfide bond, Glycoprotein, Methylation, Phosphoprotein

Proteomic databases

MaxQBiP11911.
PaxDbiP11911.
PRIDEiP11911.

PTM databases

iPTMnetiP11911.
PhosphoSitePlusiP11911.

Expressioni

Tissue specificityi

B-cells.

Gene expression databases

BgeeiENSMUSG00000003379.
CleanExiMM_CD79A.
GenevisibleiP11911. MM.

Interactioni

Subunit structurei

Heterodimer of alpha and beta chains; disulfide-linked. Part of the B-cell antigen receptor complex where the alpha/beta chain heterodimer is non-covalently associated with an antigen-specific membrane-bound surface immunoglobulin of two heavy chains and two light chains. Interacts through its phosphorylated ITAM domain with the SH2 domains of SYK which stimulates SYK autophosphorylation and activation. Also interacts, when phosphorylated on Tyr-204, with the SH2 domain of BLNK/SLP65, bringing BLNK into proximity with SYK and allowing SYK to phosphorylate BLNK which is necessary for trafficking of the BCR to late endosomes. Interacts with Src-family tyrosine kinases including FYN and LYN, increasing their activity.8 Publications

GO - Molecular functioni

Protein-protein interaction databases

BioGridi198611. 3 interactors.
DIPiDIP-61170N.
ELMiP11911.
IntActiP11911. 1 interactor.
STRINGi10090.ENSMUSP00000003469.

Structurei

3D structure databases

ProteinModelPortaliP11911.
SMRiP11911.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini29 – 117Ig-like C2-typeAdd BLAST89
Domaini171 – 199ITAMPROSITE-ProRule annotationAdd BLAST29

Keywords - Domaini

Immunoglobulin domain, Signal, Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiENOG410IV8X. Eukaryota.
ENOG4111VIC. LUCA.
GeneTreeiENSGT00510000049127.
HOGENOMiHOG000074307.
HOVERGENiHBG050854.
InParanoidiP11911.
KOiK06506.
OMAiEGTKNRI.
OrthoDBiEOG091G10RQ.
PhylomeDBiP11911.
TreeFamiTF336032.

Family and domain databases

Gene3Di2.60.40.10. 1 hit.
InterProiView protein in InterPro
IPR007110. Ig-like_dom.
IPR013783. Ig-like_fold.
IPR003599. Ig_sub.
IPR013151. Immunoglobulin.
IPR003110. Phos_immunorcpt_sig_ITAM.
PfamiView protein in Pfam
PF00047. ig. 1 hit.
PF02189. ITAM. 1 hit.
SMARTiView protein in SMART
SM00409. IG. 1 hit.
SM00077. ITAM. 1 hit.
SUPFAMiSSF48726. SSF48726. 1 hit.
PROSITEiView protein in PROSITE
PS50835. IG_LIKE. 1 hit.
PS51055. ITAM_1. 1 hit.

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P11911-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MPGGLEALRA LPLLLFLSYA CLGPGCQALR VEGGPPSLTV NLGEEARLTC
60 70 80 90 100
ENNGRNPNIT WWFSLQSNIT WPPVPLGPGQ GTTGQLFFPE VNKNHRGLYW
110 120 130 140 150
CQVIENNILK RSCGTYLRVR NPVPRPFLDM GEGTKNRIIT AEGIILLFCA
160 170 180 190 200
VVPGTLLLFR KRWQNEKFGV DMPDDYEDEN LYEGLNLDDC SMYEDISRGL
210 220
QGTYQDVGNL HIGDAQLEKP
Length:220
Mass (Da):24,583
Last modified:July 24, 2007 - v2
Checksum:iA4C648C2BE6D3E38
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti95 – 100HRGLYW → TGACTG in CAA31801 (PubMed:2463161).Curated6
Sequence conflicti95 – 100HRGLYW → TGACTG in AAA39494 (PubMed:2358676).Curated6

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X13450 mRNA. Translation: CAA31801.1.
M31773 Genomic DNA. Translation: AAA39494.1.
BC027633 mRNA. Translation: AAH27633.1.
S59359 Genomic DNA. No translation available.
CCDSiCCDS20967.1.
PIRiA43540.
RefSeqiNP_031681.2. NM_007655.3.
UniGeneiMm.1355.

Genome annotation databases

EnsembliENSMUST00000003469; ENSMUSP00000003469; ENSMUSG00000003379.
GeneIDi12518.
KEGGimmu:12518.
UCSCiuc009fqt.1. mouse.

Similar proteinsi

Entry informationi

Entry nameiCD79A_MOUSE
AccessioniPrimary (citable) accession number: P11911
Secondary accession number(s): Q6GTY0
Entry historyiIntegrated into UniProtKB/Swiss-Prot: October 1, 1989
Last sequence update: July 24, 2007
Last modified: August 30, 2017
This is version 168 of the entry and version 2 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. MGD cross-references
    Mouse Genome Database (MGD) cross-references in UniProtKB/Swiss-Prot