STAP-2 Adaptor Protein Regulates Multiple Steps of Immune and Inflammatory Responses.

Signal-transducing adaptor protein (STAP)-2 is an adaptor molecule involved in regulation of several intracellular signaling events in immune cells. STAP-2 contains a pleckstrin homology domain at the N-terminus, an src homology domain in the central portion and a proline-rich region at the C-terminus. STAP-2 also has a YXXQ motif, which is a potential signal transducer and activator of transcription (STAT)3-binding site. STAP-2 influences the STAT3 and STAT5 activity, integrin-mediated T cell adhesion, chemokine-induced T cell migration, Fas-mediated T cell apoptosis, Toll-like receptor-mediated macrophage functions, macrophage colony-stimulating factor-induced macrophage activation, and the high-affinity immunoglobulin E receptor-mediated mast cell activation. This article reviews the current understanding of roles of the STAP-2 during immune and/or inflammatory responses, and discusses possible therapeutic applications of targeting STAP-2 proteins in immune-related disorders.