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Protein

B-cell antigen receptor complex-associated protein alpha chain

Gene

CD79A

Organism
Homo sapiens (Human)
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.2 Publications

Sites

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

GO - Molecular functioni

GO - Biological processi

Complete GO annotation...

Keywords - Biological processi

Adaptive immunity, Immunity

Enzyme and pathway databases

BioCyciZFISH:ENSG00000105369-MONOMER.
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

HGNCiHGNC:1698. CD79A.

Subcellular locationi

  • Cell membrane; Single-pass type I membrane protein

  • Note: Following antigen binding, the BCR has been shown to translocate from detergent-soluble regions of the cell membrane to lipid rafts although signal transduction through the complex can also occur outside lipid rafts.By similarity

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini33 – 143ExtracellularSequence analysisAdd BLAST111
Transmembranei144 – 165HelicalSequence analysisAdd BLAST22
Topological domaini166 – 226CytoplasmicSequence analysisAdd BLAST61

GO - Cellular componenti

Complete GO annotation...

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...)Sequence analysis1
Glycosylationi63N-linked (GlcNAc...)Sequence analysis1
Glycosylationi73N-linked (GlcNAc...)Sequence analysis1
Glycosylationi88N-linked (GlcNAc...)Sequence analysis1
Glycosylationi97N-linked (GlcNAc...)Sequence analysis1
Glycosylationi112N-linked (GlcNAc...)Sequence 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.
HPA017748.

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

WithEntry#Exp.IntActNotes
FATE1Q969F05EBI-7797864,EBI-743099

Protein-protein interaction databases

BioGridi107411. 43 interactors.
IntActiP11912. 2 interactors.
MINTiMINT-6491159.
STRINGi9606.ENSP00000221972.

Structurei

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1CV9NMR-A184-195[»]
DisProtiDP00502.
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

Sequence similaritiesi

Contains 1 ITAM domain.PROSITE-ProRule annotation

Keywords - Domaini

Immunoglobulin domain, Signal, Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiENOG410IV8X. Eukaryota.
ENOG4111VIC. LUCA.
GeneTreeiENSGT00510000049127.
HOGENOMiHOG000074307.
HOVERGENiHBG050854.
InParanoidiP11912.
KOiK06506.
OMAiRKRWQNE.
PhylomeDBiP11912.
TreeFamiTF336032.

Family and domain databases

Gene3Di2.60.40.10. 1 hit.
InterProiIPR007110. Ig-like_dom.
IPR013783. Ig-like_fold.
IPR003599. Ig_sub.
IPR003598. Ig_sub2.
IPR013151. Immunoglobulin.
IPR003110. Phos_immunorcpt_sig_ITAM.
[Graphical view]
PfamiPF00047. ig. 1 hit.
PF02189. ITAM. 1 hit.
[Graphical view]
SMARTiSM00409. IG. 1 hit.
SM00408. IGc2. 1 hit.
SM00077. ITAM. 1 hit.
[Graphical view]
SUPFAMiSSF48726. SSF48726. 1 hit.
PROSITEiPS50835. IG_LIKE. 1 hit.
PS51055. ITAM_1. 1 hit.
[Graphical view]

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

Cross-referencesi

Web resourcesi

CD79Abase

CD79A mutation db

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.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1CV9NMR-A184-195[»]
DisProtiDP00502.
ProteinModelPortaliP11912.
SMRiP11912.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi107411. 43 interactors.
IntActiP11912. 2 interactors.
MINTiMINT-6491159.
STRINGi9606.ENSP00000221972.

PTM databases

iPTMnetiP11912.
PhosphoSitePlusiP11912.

Polymorphism and mutation databases

BioMutaiCD79A.
DMDMi547896.

Proteomic databases

EPDiP11912.
MaxQBiP11912.
PaxDbiP11912.
PeptideAtlasiP11912.
PRIDEiP11912.

Protocols and materials databases

DNASUi973.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

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

Organism-specific databases

CTDi973.
DisGeNETi973.
GeneCardsiCD79A.
HGNCiHGNC:1698. CD79A.
HPAiCAB000019.
HPA017748.
MalaCardsiCD79A.
MIMi112205. gene.
613501. phenotype.
neXtProtiNX_P11912.
OpenTargetsiENSG00000105369.
Orphaneti33110. Autosomal agammaglobulinemia.
PharmGKBiPA26237.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiENOG410IV8X. Eukaryota.
ENOG4111VIC. LUCA.
GeneTreeiENSGT00510000049127.
HOGENOMiHOG000074307.
HOVERGENiHBG050854.
InParanoidiP11912.
KOiK06506.
OMAiRKRWQNE.
PhylomeDBiP11912.
TreeFamiTF336032.

Enzyme and pathway databases

BioCyciZFISH:ENSG00000105369-MONOMER.
ReactomeiR-HSA-5690714. CD22 mediated BCR regulation.
R-HSA-983695. Antigen activates B Cell Receptor (BCR) leading to generation of second messengers.
SignaLinkiP11912.
SIGNORiP11912.

Miscellaneous databases

EvolutionaryTraceiP11912.
GeneWikiiCD79A.
GenomeRNAii973.
PROiP11912.
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000105369.
CleanExiHS_CD79A.
ExpressionAtlasiP11912. baseline and differential.
GenevisibleiP11912. HS.

Family and domain databases

Gene3Di2.60.40.10. 1 hit.
InterProiIPR007110. Ig-like_dom.
IPR013783. Ig-like_fold.
IPR003599. Ig_sub.
IPR003598. Ig_sub2.
IPR013151. Immunoglobulin.
IPR003110. Phos_immunorcpt_sig_ITAM.
[Graphical view]
PfamiPF00047. ig. 1 hit.
PF02189. ITAM. 1 hit.
[Graphical view]
SMARTiSM00409. IG. 1 hit.
SM00408. IGc2. 1 hit.
SM00077. ITAM. 1 hit.
[Graphical view]
SUPFAMiSSF48726. SSF48726. 1 hit.
PROSITEiPS50835. IG_LIKE. 1 hit.
PS51055. ITAM_1. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiCD79A_HUMAN
AccessioniPrimary (citable) accession number: P11912
Secondary accession number(s): A0N775, Q53FB8
Entry historyi
Integrated into UniProtKB/Swiss-Prot: October 1, 1989
Last sequence update: June 1, 1994
Last modified: November 30, 2016
This is version 167 of the entry and version 2 of the sequence. [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
  5. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.