THE NCK SH2 SH3 ADAPTER PROTEIN - A REGULATOR OF MULTIPLE INTRACELLULAR SIGNAL-TRANSDUCTION EVENTS/

The process generally termed signal transduction involves the coordina ted relay of information from extracellular cues to intracellular effe cters, subsequently leading to a specified cellular response. The form ation of multimeric protein complexes is a critical step in the activa tion of most intracellular signal transduction cascades. In many cases , these processes are initiated by a family of molecules consisting of protein association motifs known as src homology 2 and 3 (SH2 and SH3 ) domains. This review focuses on a group of proteins within this fami ly that lack intrinsic enzymatic functions and consist almost entirely of SH2 and SH3 domains. Termed ''adaptors,'' these proteins serve to physically bridge activated cell surface receptors to various intracel lular signal transduction pathways. Here, I briefly summarize current knowledge concerning the various adaptor proteins and place a particul ar emphasis on Nck. Various data are discussed which collectively supp ort a role for Nck in the regulation of multiple intracellular signali ng events. (C) 1998 John Wiley & Sons, Inc.