Signal transduction by B lymphocyte receptors: structure-function relationships of membrane immunoglobulins and associated molecules.

Membrane immunoglobulins function in transmembrane transduction of information leading to gene activation and to receptor desensitization. These receptors also function in focusing and internalization of antigen for subsequent processing and presentation to T cells. These functions require that antigen receptors communicate physically with molecules in the cytoplasm. Recent evidence suggests that this is accomplished via an mIg-associated protein complex analogous to T cell CD3. Here we review evidence regarding the molecular basis of signal transduction by mIg and the structure of mIg-associated proteins which may be involved in signal transduction.