Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

B-cell antigen receptor complex-associated protein alpha chain

Gene

CD79A

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -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.2 Publications

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei210Required for binding to BLNKBy similarity1

GO - Molecular functioni

  • protein homodimerization activity Source: CAFA
  • transmembrane signaling receptor activity Source: InterPro

GO - Biological processi

Keywordsi

Biological processAdaptive immunity, Immunity

Enzyme and pathway databases

ReactomeiR-HSA-5690714 CD22 mediated BCR regulation
R-HSA-983695 Antigen activates B Cell Receptor (BCR) leading to generation of second messengers
SignaLinkiP11912
SIGNORiP11912

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, MB1
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 19

Organism-specific databases

EuPathDBiHostDB:ENSG00000105369.9
HGNCiHGNC:1698 CD79A
MIMi112205 gene
neXtProtiNX_P11912

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 domaini33 – 143ExtracellularSequence analysisAdd BLAST111
Transmembranei144 – 165HelicalSequence analysisAdd BLAST22
Topological domaini166 – 226CytoplasmicSequence analysisAdd BLAST61

Keywords - Cellular componenti

Cell membrane, Membrane

Pathology & Biotechi

Involvement in diseasei

Agammaglobulinemia 3, autosomal recessive (AGM3)2 Publications
The disease is caused by mutations affecting the gene represented in this entry. Two different mutations, one at the splice donor site of intron 2 and the other at the splice acceptor site for exon 3, have been identified. Both mutations give rise to a truncated protein.
Disease descriptionA primary immunodeficiency characterized by profoundly low or absent serum antibodies and low or absent circulating B-cells due to an early block of B-cell development. Affected individuals develop severe infections in the first years of life.
See also OMIM:613501

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi197S → A: Increased phosphorylation of Y-188; when associated with A-203 and V-209. 1 Publication1
Mutagenesisi203S → A: Increased phosphorylation of Y-188; when associated with A-197 and V-209. 1 Publication1
Mutagenesisi209T → V: Increased phosphorylation of Y-188; when associated with A-197 and A-203. 1 Publication1

Organism-specific databases

DisGeNETi973
MalaCardsiCD79A
MIMi613501 phenotype
OpenTargetsiENSG00000105369
Orphaneti33110 Autosomal agammaglobulinemia
PharmGKBiPA26237

Polymorphism and mutation databases

BioMutaiCD79A
DMDMi547896

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 321 PublicationAdd BLAST32
ChainiPRO_000001455833 – 226B-cell antigen receptor complex-associated protein alpha chainAdd BLAST194

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi54 ↔ 106PROSITE-ProRule annotation
Glycosylationi57N-linked (GlcNAc...) asparagineSequence analysis1
Glycosylationi63N-linked (GlcNAc...) asparagineSequence analysis1
Glycosylationi73N-linked (GlcNAc...) asparagineSequence analysis1
Glycosylationi88N-linked (GlcNAc...) asparagineSequence analysis1
Glycosylationi97N-linked (GlcNAc...) asparagineSequence analysis1
Glycosylationi112N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi119Interchain (with C-136 in beta chain)PROSITE-ProRule annotation
Modified residuei188Phosphotyrosine; by SRC-type Tyr-kinasesPROSITE-ProRule annotationBy similarity1
Modified residuei199Phosphotyrosine; by SRC-type Tyr-kinasesPROSITE-ProRule annotationBy similarity1
Modified residuei204Asymmetric dimethylarginine; by PRMT1By similarity1
Modified residuei210Phosphotyrosine; by Tyr-kinasesPROSITE-ProRule annotationBy similarity1

Post-translational modificationi

Phosphorylated on tyrosine, serine and threonine residues upon B-cell activation. Phosphorylation of tyrosine residues by Src-family kinases 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. Phosphorylated by LYN. Phosphorylation of serine and threonine residues may prevent subsequent tyrosine phosphorylation.2 Publications
Arginine methylation in the ITAM domain may interfere with the binding of SYK. It promotes signals leading to B-cell differentiation (By similarity).By similarity

Keywords - PTMi

Disulfide bond, Glycoprotein, Methylation, Phosphoprotein

Proteomic databases

EPDiP11912
MaxQBiP11912
PaxDbiP11912
PeptideAtlasiP11912
PRIDEiP11912

PTM databases

iPTMnetiP11912
PhosphoSitePlusiP11912

Expressioni

Tissue specificityi

B-cells.

Gene expression databases

BgeeiENSG00000105369
CleanExiHS_CD79A
ExpressionAtlasiP11912 baseline and differential
GenevisibleiP11912 HS

Organism-specific databases

HPAiCAB000019

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-210, 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 (By similarity).By similarity

Binary interactionsi

Show more details

GO - Molecular functioni

  • protein homodimerization activity Source: CAFA

Protein-protein interaction databases

BioGridi107411, 53 interactors
ELMiP11912
IntActiP11912, 4 interactors
MINTiP11912
STRINGi9606.ENSP00000221972

Structurei

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1CV9NMR-A184-195[»]
ProteinModelPortaliP11912
SMRiP11912
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP11912

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini33 – 116Ig-like C2-typeAdd BLAST84
Domaini177 – 205ITAMPROSITE-ProRule annotationAdd BLAST29

Keywords - Domaini

Immunoglobulin domain, Signal, Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiENOG410IV8X Eukaryota
ENOG4111VIC LUCA
GeneTreeiENSGT00510000049127
HOGENOMiHOG000074307
HOVERGENiHBG050854
InParanoidiP11912
KOiK06506
OMAiEGTKNRI
PhylomeDBiP11912
TreeFamiTF336032

Family and domain databases

Gene3Di2.60.40.10, 1 hit
InterProiView protein in InterPro
IPR007110 Ig-like_dom
IPR036179 Ig-like_dom_sf
IPR013783 Ig-like_fold
IPR003599 Ig_sub
IPR003598 Ig_sub2
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
SM00408 IGc2, 1 hit
SM00077 ITAM, 1 hit
SUPFAMiSSF48726 SSF48726, 1 hit
PROSITEiView protein in PROSITE
PS50835 IG_LIKE, 1 hit
PS51055 ITAM_1, 1 hit

Sequences (2)i

Sequence statusi: Complete.

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

This entry describes 2 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: P11912-1) [UniParc]FASTAAdd to basket
Also known as: Long

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

« Hide

        10         20         30         40         50
MPGGPGVLQA LPATIFLLFL LSAVYLGPGC QALWMHKVPA SLMVSLGEDA
60 70 80 90 100
HFQCPHNSSN NANVTWWRVL HGNYTWPPEF LGPGEDPNGT LIIQNVNKSH
110 120 130 140 150
GGIYVCRVQE GNESYQQSCG TYLRVRQPPP RPFLDMGEGT KNRIITAEGI
160 170 180 190 200
ILLFCAVVPG TLLLFRKRWQ NEKLGLDAGD EYEDENLYEG LNLDDCSMYE
210 220
DISRGLQGTY QDVGSLNIGD VQLEKP
Length:226
Mass (Da):25,038
Last modified:June 1, 1994 - v2
Checksum:i6E5B837409969292
GO
Isoform 2 (identifier: P11912-2) [UniParc]FASTAAdd to basket
Also known as: Short

The sequence of this isoform differs from the canonical sequence as follows:
     89-127: GTLIIQNVNKSHGGIYVCRVQEGNESYQQSCGTYLRVRQ → E

Show »
Length:188
Mass (Da):20,786
Checksum:i176B170B710E6EEB
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti47G → V in BAD97091 (Ref. 10) Curated1
Sequence conflicti69V → I in AAA60270 (PubMed:1639443).Curated1
Sequence conflicti189E → G in BAD97091 (Ref. 10) Curated1

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Alternative sequenceiVSP_00247689 – 127GTLII…LRVRQ → E in isoform 2. 2 PublicationsAdd BLAST39

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
S46706 mRNA Translation: AAB23558.1
M80462 mRNA Translation: AAA59556.1
M74721 mRNA Translation: AAA60270.1
S75217 mRNA Translation: AAB20812.1
M86921 mRNA Translation: AAA59557.1
U05259 Genomic DNA Translation: AAA20495.1
S79248 mRNA Translation: AAC60653.1
X83540 mRNA Translation: CAA58523.1
AK223371 mRNA Translation: BAD97091.1
X13451 mRNA Translation: CAA31802.1 Sequence problems.
CCDSiCCDS12589.1 [P11912-1]
CCDS46088.1 [P11912-2]
PIRiI54539 A46477
S12504
RefSeqiNP_001774.1, NM_001783.3 [P11912-1]
NP_067612.1, NM_021601.3 [P11912-2]
UniGeneiHs.631567

Genome annotation databases

EnsembliENST00000221972; ENSP00000221972; ENSG00000105369 [P11912-1]
ENST00000444740; ENSP00000400605; ENSG00000105369 [P11912-2]
GeneIDi973
KEGGihsa:973
UCSCiuc002oru.4 human [P11912-1]

Keywords - Coding sequence diversityi

Alternative splicing

Similar proteinsi

Entry informationi

Entry nameiCD79A_HUMAN
AccessioniPrimary (citable) accession number: P11912
Secondary accession number(s): A0N775, Q53FB8
Entry historyiIntegrated into UniProtKB/Swiss-Prot: October 1, 1989
Last sequence update: June 1, 1994
Last modified: February 28, 2018
This is version 175 of the entry and version 2 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. Human cell differentiation molecules
    CD nomenclature of surface proteins of human leucocytes and list of entries
  2. Human chromosome 19
    Human chromosome 19: entries, gene names and cross-references to MIM
  3. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  4. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health