14-3-3 and its possible role in co-ordinating multiple signalling pathways.

Members of the 14-3-3 family are homo- and the heterodimeric proteins mediating interaction between diverse components of many biological activities. The role of these proteins has been unclear for some time, but they are now gaining acceptance as a novel type of chaperone protein that modulates interactions between components of signal-transduction pathways. It is becoming apparent from recent studies that phosphorylation of the binding partner and possibly also the 14-3-3 proteins themselves is important in regulating these interactions. Analysis of the major sites of phosphorylation in Raf has led to the identification of a novel sequence motif, R(S)X(1,2)S(P)X(P), that may represent a conserved interaction site for 14-3-3-binding proteins.