I am studying the role of mitogen-activated protein kinases (MAPK's) in the reulation of cell proliferation and apoptosis. The serine/threonine kinase RSK is a target of the MAPK pathway. In the laboratory of Dr. John Blenis, I have identified a novel role for RSK in promoting cell survival. One mechanism for RSK-mediated cell survival is the direct phosphorylation and subsequent inactivation of BAD, a pro-apoptotic member of the Bcl-2 family. RSK has been reported to phosphorylate additional apoptosis regulatory proteins, such as CREB and IKB, so RSK likely promotes cell survival through pathways in addition to BAD. RSK also phosphorylates the cell cycle regulatory protein myt1. I am investigating the biochemical mechanisms regulating RSK activity. I am also conducting studies to identify interactions between RSK and other key regulatory kinases. Finally, I have developed a novel constitutively active RSK mutant and am conducting experiments to investigate RSK's role in oncogenesis both in cell culture and in tumors.