CELL CYCLE ARREST AND SIGNAL TRANSDUCTION IN YEAST

酵母交配途径为负生长提供了一个极好的范例。 高等真核生物的调控和分化。建议的目标是 研究是为了定义一种进化上保守的蛋白激酶FUS3， 发挥调节细胞周期和信号的关键功能 交配和营养生长过程中的转导。现建议将一项 将遗传和生化方法相结合，以努力 确定：a)FUS3如何同时阻止有丝分裂细胞周期 通过抑制G1-细胞周期蛋白和激活受体/G蛋白- 耦合信号转导途径；B)功能的基础 FUS3和同源蛋白激酶KSS1之间的冗余 这也促进了信号转导。为了实现这些目标， 该提案的具体目标是：1)诱变FUS3以识别 指定其多重功能的蛋白质结构域，并为其制造突变体 随后的目标。2)使用FUS3免疫复合酶检测 生理上相关的蛋白质是否被FUS3磷酸化 在体外或在体内与FUS3相关，并检测FUS3是如何 在体外和体内都有调节。3)鉴定下列蛋白质： 与FUS3相互作用或通过基因筛选是其功能同源物。

The yeast mating pathway provides an excellent paradigm for negative growth control and differentiation in higher eukaryotes. The goal of the proposed research is to define how an evolutionarily conserved protein kinase, FUS3, exerts critical functions which regulate the cell cycle and signal transduction during mating and vegetative growth. It is proposed that a combination of genetic and biochemical approaches be taken in an effort to determine: A) How FUS3 simultaneously arrests the mitotic cell cycle through inhibition of a G1-cyclins and activates a receptor/G protein- coupled signal transduction pathway; B) The basis of the functional redundancy between FUS3 and KSS1, a homologous putative protein kinase which also promotes signal transduction. To accomplish these goals, the specific aims of the proposal are: 1) To mutagenize FUS3 to identify the protein domains that specify its multiple functions and to make mutants for subsequent aims. 2) To use a FUS3 immune complex kinase assay to test whether physiologically relevant proteins are either phosphorylated by FUS3 in vitro or associated with FUS3 in vivo, and to examine how FUS3 is regulated in vitro and in vivo. 3) To identify proteins which either interact with FUS3 or are its functional homologues by genetic screens.