CD79 is composed of two distinct chains called CD79A and CD79B (also known as Igα and Igβ); these form a heterodimer on the surface of a B cell stabilized by disulfide bonding.
[4] In addition, both CD79 chains contain an immunoreceptor tyrosine-based activation motif (ITAM), which some scientists have found to propagate downstream signaling in B-cells.
[7] Hardy et al. found that upon an Ag-induced BCR aggregation, CD79 is phosphorylated and initiates a cascade of downstream signaling events.
Hardy et al. further characterized an alternate mode of BCR signaling that is induced by chronic AgR stimulation and maintains a state of B cell unresponsiveness termed "anergy".
Activation of the BCR with T-cell-dependent (TD) or TI antigens induces cross-linking of surface Ig molecules and binding to the transmembrane protein CD79.