CD79B

Domain

The transmembrane helices of CD79A and CD79B chains and two IgM heavy chains assembly in a four-helix bundle structure that appears to be conserved among different BCR isotypes.

Function

Required in cooperation with CD79A for initiation of the signal transduction cascade activated by the B-cell antigen receptor complex (BCR) which leads to internalization of the complex, trafficking to late endosomes and antigen presentation. Enhances phosphorylation of CD79A, possibly by recruiting kinases which phosphorylate CD79A or by recruiting proteins which bind to CD79A and protect it from dephosphorylation.

Involvement in disease

Agammaglobulinemia 6, autosomal recessive

AGM6

A 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.

None

The disease is caused by variants affecting the gene represented in this entry.

Post-translational modifications

Phosphorylated on tyrosine upon B-cell activation by SRC-type Tyr-kinases such as BLK, LYN and SYK.

Tissue Specificity

B-cells.

Cellular localization

• Cell membrane
• Single-pass type I membrane protein
• 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.

Alternative names

CD79b, B29, IGB, CD79B, B-cell antigen receptor complex-associated protein beta chain, B-cell-specific glycoprotein B29, Ig-beta, Immunoglobulin-associated B29 protein

Database links

swissprot:P40259 entrezGene:974 omim:147245

Other research areas

• Immunology & Infectious Disease