Kathleen L. Gould
Our group is studying cell cycle control in the yeast, Schizosaccharomyces pombe. We are particularly interested in two aspects of cell cycle control: 1)entry into mitosis and 2)the mechanism of cytokinesis.
Entry into mitosis is governed by the activation of the Cdc2/Cdc13(cyclin B) protein kinase complex. We are examining biochemically some of the steps in the regulatory pathway of protein kinases which control the timing of Cdc2 activation. We are also searching genetically for substrates of this complex which presumably bring about the complex events of mitosis. Another gene product which plays an essential role in the entry into mitosis is the c-Myb-related Cdc5 protein. The Cdc5 protein is part of a large protein complex and we are trying to identify the associated factors and also the downstream targets of Cdc5. Relatives of Cdc5 have now been identified in budding yeast and vertebrates and we are pursuing whether these proteins are functionally homologous. Finally, our group has isolated some of the genes required for the formation of an F-actin contractile ring including profilin and a non-conventional myosin light chain. Suppressor analyses of mutations in these genes have identified two components of a complex which is necessary for actin filament function and includes the actin related proteins arp2 and arp3. Through continuing analysis of these proteins and others which interact with them, we hope to learn more about the coordination of cell growth, nuclear division and cytokinesis.