Chimaerins: GAPs that bridge diacylglycerol signalling and the small G-protein Rac.
Chimaerins are the only known RhoGAPs (Rho GTPase-activating proteins) that bind phorbol ester tumour promoters and the lipid second messenger DAG (diacylglycerol), and show specific GAP activity towards the small GTPase Rac. This review summarizes our knowledge of the structure, biochemical and biological properties of chimaerins. Recent findings have established that chimaerins are regulated by tyrosine kinase and GPCRs (G-protein-coupled receptors) via PLC (phospholipase C) activation and DAG generation to promote Rac inactivation. The finding that chimaerins, along with some other proteins, are receptors for DAG changed the prevalent view that PKC (protein kinase C) isoenzymes are the only cellular molecules regulated by DAG. In addition, vigorous recent studies have begun to decipher the critical roles of chimaerins in the central nervous system, development and tumour progression.
Yang
Chengfeng
C
Department of Pharmacology and Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160, USA. cfyang@spirit.gcrc.upenn.edu
Kazanietz
Marcelo G
MG
D000818:Animals; D002455:Cell Division; D020740:Chimerin Proteins / Q000502:physiology*; D004075:Diglycerides / Q000502:physiology*; D008325:Mammary Neoplasms, Experimental / Q000473:pathology / Q000503:physiopathology; D009024:Morphogenesis; D009474:Neurons / Q000502:physiology; D015398:Signal Transduction; D020744:rac GTP-Binding Proteins / Q000502:physiology*
D020740:Chimerin Proteins; D004075:Diglycerides; D020744:rac GTP-Binding Proteins