CD79B; B-cell antigen receptor complex-associated protein beta chain; Ig-beta; B-cell-specific glycoprotein B29; immunoglobulin-associated B29 protein (B29. IGB)

Function

• component of B-cell antigen receptor (BCR)
• 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 & antigen presentation
• enhances phosphorylation of CD79A, possibly by recruiting kinases which phosphorylate CD79A or by recruiting proteins which bind to CD79A & protect it from dephosphorylation
• phosphorylated on Tyr upon B-cell activation
• part of the B-cell antigen receptor complex where the alpha/beta chain heterodimer is non-covalently associated with antigen-specific membrane-bound surface immunoglobulin of two heavy chains & two light chains

Structure

• heterodimer of alpha & beta chains; disulfide-linked
• contains 1 Ig-like V-type domain (immunoglobulin-like)
• contains 1 ITAM domain

Compartment

• cell membrane; single-pass type I membrane protein
• following antigen binding, the B-cell receptor translocates from detergent-soluble regions of the cell membrane to lipid rafts although signal transduction through the complex can also occur outside lipid rafts (putative)

Alternative splicing

named isoforms=2

Expression

B-cells

Pathology

• defects in CD79B are a cause of hypogammaglobulinemia immunodeficiency & reduced B cells

More general terms

• plasma membrane protein
• glycoprotein
• protein subunit

Component of

• CD79 or B-cell antigen receptor complex-associated protein

Database

• UniProt: http://www.uniprot.org/uniprot/P40259.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=974
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:974
• OMIM: https://mirror.omim.org/entry/147245
• OMIM: https://mirror.omim.org/entry/612692