Long & Medium Term Research: Cyclin Destruction in Meiotic and Early Mitotic Cell Cycles of Xenopus Laevis

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Long & Medium-Term Research: Cyclin Destruction in Meiotic and Early Mitotic Cell Cycles of Xenopus Laevis This award recommendation is made under the Program for Long & Medium-Term Research at Foreign Centers of Excellence. The program seeks to enable U.S. scientists and engineers to conduct long-term research abroad at research institutions of proven excellence. Awards provide opportunities for the conduct of joint research, and the use of unique or compli- mentary facilities, expertise and experimental conditions in foreign countries. This award for a proposal sponsored by Dr. Jolinda A. Traugh, will support a 12-month postdoctoral research visit by Dr. Elizabeth Mandley to the United Kingdom to work with Dr. Michael Whitaker of the Department of Physiology of the University of the City of London, on "Cyclin Destruction in Meiotic and Early Mitotic Cell Cycles of Sea Urchins (Xenopus)." The investigators propose to investigate the mechanism of cyclin destruction during the M-phase of the rapid cell cycles of early sea urchin development. Cyclin is only unstable during M-phase, and preliminary evidence implicates a regulatory cascade of protein phosphorylation and desphosphorylation in the process. Some evidence suggests calcium may be involved in the destruction process. Cyclin destruction can be triggered in a cell-free system prepared from Xenopus eggs by addition of active cyclin/p34-cdc2 complex. Destruction requires ATP and the participation of both soluble and particulate material. This suggests that the high molecular weight multifunctional protease and hence ubiquitin may be involved. The investigators will investigate whether cylcin degradation involves ubiquitin by searching for ubiquitinated intermediates of cyclin, and by fractiona- tion. They will also investigate the role that calcium plays in the destruction process. More generally, they will attempt to purify and identify as far as possible the components of the destruction system. The award recommendation provides funds to cover, as appropriate, international travel, local travel abroad, stipend, dependents' allowance if applicable, and a flat administrative allowance of $250 for the U.S. home institution.