CD79A Protein, Cynomolgus (HEK293, His)

CD79A, in collaboration with CD79B, plays a pivotal role in initiating the signal transduction cascade triggered by antigen binding to the B-cell antigen receptor complex (BCR), resulting in the internalization of the complex, trafficking to late endosomes, and subsequent antigen presentation. This indispensable protein is also crucial for BCR surface expression and the efficient differentiation of pro- and pre-B-cells. CD79A not only stimulates SYK autophosphorylation and activation but also binds to BLNK, facilitating the proximity of BLNK to SYK and enabling the phosphorylation of BLNK. Additionally, it interacts with and enhances the activity of specific Src-family tyrosine kinases, including FYN and LYN. In the context of immature B-cell development, CD79A functions to repress BCR signaling. As a heterodimer of alpha and beta chains, CD79A forms a disulfide-linked complex within the B-cell antigen receptor, where the alpha/beta chain heterodimer non-covalently associates with an antigen-specific membrane-bound surface immunoglobulin composed of two heavy chains and two light chains. The interaction through its phosphorylated ITAM domain with the SH2 domains of SYK stimulates SYK autophosphorylation and activation. Furthermore, when phosphorylated on Tyr-204, CD79A interacts with the SH2 domain of BLNK/SLP65, bringing BLNK into proximity with SYK and facilitating the phosphorylation of BLNK, a critical step for the trafficking of the BCR to late endosomes. CD79A's versatile interactions contribute to the intricate regulation of B-cell signaling and function.