Modulation of STAT signaling by STAT-interacting proteins

STATs (signal transducer and activator of transcription) play important rol es in numerous cellular processes including immune responses, cell growth a nd differentiation, cell survival and apoptosis, and oncogenesis. In contra st to many other cellular signaling cascades, the STAT pathway is direct: S TATs bind to receptors at the cell surface and translocate into the nucleus where they function as transcription factors to trigger gene activation, H owever, STATs do not act alone. A number of proteins are found to be associ ated with STATs, These STAT-interacting proteins function to modulate STAT signaling at various steps and mediate the crosstalk of STATs with other ce llular signaling pathways. This article reviews the roles of STAT-interacti ng proteins in the regulation of STAT signaling.