Daria Mochly-Rosen






		Daria Mochly-Rosen Title Professor Department Molecular Pharmacology Research Interests Mechanisms underlying the specificity of protein kinase C isozymes; protein kinase C in ischemia, stroke and other pathological scenarios. Email mochly@stanford.edu Phone 725-7720 Fax 723-2253 Address CCSR 3145A Mail Code: 5174 http://www.stanford.edu/group/mochly-rosen/ Faculty Research Description We are studying the mechanism of protein kinase C-mediated signal transduction in several disease models. Based on our recent data, we proposed a working hypothesis that activated PKC isozymes bind to intracellular receptor proteins located at different subcellular sites, and that these receptors differentially bind specific PKC isozymes. Evidence was obtained for the presence of intracellular receptor proteins that bind activated PKC. Binding of PKC to these proteins was concentration-dependent, saturable and specific, suggesting that these binding proteins are receptors for activated C-kinase, or "RACKs". We have characterized and cloned several RACKs and identified domains in different PKC isozymes that are required for the specific association with these RACKs; these domains are distinct from the substrate binding site on PKC. On the basis of this information, together with computer modeling of crystal structures of the interacting proteins, we have identified novel isozyme-selective inhibitors that inhibit translocation and the consequent function of individual PKC isozymes. These inhibitors are fragments of PKC or RACKs that have 'dominant negative' activities on PKC binding to RACKs and on their activities, in vivo. In addition, we prepared synthetic peptides corresponding to the binding sites in PKC and RACKs. We are currently determining the effects of these isozyme-selective translocation inhibitors on a number of PKC-mediated cell functions in normal and diseased heart. These include cardiac and smooth muscle cell contraction, gene expression, hypertrophy, and response to and protection from ischemic insult. The role of PKC in the nervous system is one of the areas of interest to the lab. PKC has been shown to be involved in the neurobiology of pain. Several isozymes of PKC are expressed differentially in peripheral and spinal cord neurons. In collaboration with the Yeomans lab in the Department of Anesthesia, we are studying the role of PKC in pain sensation and the inflammatory response associated with it using PKC isozyme- specific activator and inhibitor peptides that we have generated. The peptides are delivered transdermally or intraspinally, using novel delivery vehicles. If found to be analgesic, the peptides may provide a new therapeutic approach for the treatment of pain. Another area of investigation is the role of PKC isozymes in the response to ischemic insult to the brain. Select PKC isozymes are activated in a stroke model using cerebral focal ischemia. In collaboration with the laboratories of Drs. Yenari and Steinberg in the Dept. of Neurosurgery, we determine the role of different PKC isozymes in ischemia reperfusion damage to the CNS. To this end, PKC isozyme selective activator and inhibitor peptides are delivered IV using a new delivery method. These peptides will enable us to determine the PKC isozyme(s) that mediate protection or damage from ischemima. Our goal is to determine the molecular basis for the response to ischemic insult and identify potential novel therapeutics for the treatment of CNS ischemia and stroke. Ron D, Luo J, and MOCHLY-ROSEN D: C2 region-derived peptides inhibit translocation and function ß of protein kinase C in vivo. J. Biol. Chem. 270:24180-24187, 1995. MOCHLY-ROSEN D: Localization of protein kinases by anchoring proteins: A theme in signal transduction.Ê Science 268:247-251, 1995. Souroujon M and MOCHLY-ROSEN D: Peptide modulators of protein-protein interactions in intracellular signaling; focus on protein kinases.Ê Nature Biotechnology 16:919-924, 1998. Dorn GW, Souroujon MC, Liron T, Chen-C-H, Gray MO, Zhou HZ, Csukai M, Wu G, Lorenz JN, and MOCHLY-ROSEN D: Sustained in vivo cardiac protection by a rationally designed peptide that causes e protein kinase C translocation.Ê Proc. Natl. Acad. Sci. USA 96(22):12798-12803, 1999. Inagaki K, Lee FH, Chen L, Lyons J, Ikeno F, Bailey L, Carter A, Yeung A, Yock P, MOCHLY-ROSEN D: In vivo local delivery of a cardioprotective peptide, yeRACK, provides myocardial protection from ischemia in pigs. Proc. Natl. Acad. Sci. USA, 2001. In press. Areas of Study Cellular Neurobiology Molecular Neurobiology SBRC Ph.D.