CD79A [SEP] found in taxon
the presence of antigens on its surface.
It is associated with agammaglobulinemia-3.
Gene.
The mouse CD79A gene, then called mb-1, was cloned in the late 1980s, followed by the discovery of human CD79A in the early 1990s. It is a short gene, 4.3 kb in length, with 5 exons encoding for 2 splice variants resulting in 2 isoforms.
CD79A is conserved and abundant among ray-finned fish (actinopterygii) but not in the evolutionarily more ancient chondrichthyes such as shark. The occurrence of
CD79A thus coincides with the evolution of B cell receptors with greater diversity generated by recombination of multiple V, D, and J elements in bony fish contrasting the single V, D and J elements found in shark.
Structure.
CD79a is a membrane protein with an extracellular immunoglobulin domain, a single span transmembrane region and a short cytoplasmic domain. The cytoplasmic domain contains multiple phosphorylation sites including a conserved dual phosphotyrosine binding motif, termed immunotyrosine-based activation motif (ITAM). The larger CD79a isoform contains an insert in