THE EXTENDED PROTEIN-KINASE-C SUPERFAMILY

Members of the mammalian protein kinase C (PKC) superfamily Flay key r egulatory roles in a multitude of cellular processes, ranging from con trol of fundamental cell autonomous activities, such as proliferation, to more organismal functions, such as memory. However, understanding of mammalian PKC signalling systems is complicated by the large number of family members. Significant progress has been made through studies based on comparative analysis, which have defined a number of regulat ory elements in PKCs which confer specific location and activation sig nals to each isotype. Further studies on simple organisms have shown t hat PKC signalling paradigms are conserved through evolution from yeas t to humans, underscoring the importance of this family in cellular si gnalling and giving novel insights into PKC function in complex mammal ian systems.