NIMA PROTEIN KINASE IN MITOTIC REGULATION

描述：拟定实验旨在继续PI 丝状真菌曲霉属NimA蛋白激酶的研究 nidulans。 以前的工作，几乎完全来自PI的实验室， 证明NimA是通过有丝分裂所必需的， 由涉及磷酸化和降解的复杂机制调节。 在其他真核生物中也有一些NimA同源物的证据，表明 这种激酶通常在真核生物的控制中很重要， 分裂。 在本申请中，PI提出了一系列广泛的 这些实验将解决NimA功能的几个方面。 有 五个具体目标：（1）遗传和生物化学方法将用于 鉴定与NimA相互作用的蛋白质。 已经取得了重大进展， 索纳是一种基因外抑制因子， NimA突变。 (2)PI建议研究泛素化的作用， NimA的有丝分裂降解。 (3)NimA上的磷酸化位点将被 映射和突变，以确定其在NimA调节中的作用。 (4)的作用 将探讨NimA在S期检查点的作用。 初步实验 这表明抑制DNA合成可以阻断有丝分裂进入， 抑制NimA。 拟议的实验将描述对照的特征 Cdc2对NimA基因表达的调控以及Cdc2对NimA磷酸化的调控 BimE，一种在S期停滞期间也参与NimA控制的蛋白质。 （五） 提出实验以进一步定义NimA在 有丝分裂，强调其在纺锤体中的作用。

DESCRIPTION: The proposed experiments are designed to continue the PI's studies of the NimA protein kinase of the filamentous fungus, Aspergillus nidulans. Previous work, almost entirely from the PI's laboratory, has demonstrated that NimA is required for passage through mitosis and is regulated by complex mechanisms involving phosphorylation and degradation. There is some evidence for NimA homologues in other eukaryotes, suggesting that this kinase is generally important in the control of eukaryotic mitosis. In the present application, the PI proposes an extensive series of experiments that will address several aspects of NimA function. There are five specific aims: (1) Genetic and biochemical approaches will be used to identify proteins that interact with NimA. Significant progress has already been made toward the characterization of SonA, an extragenic suppressor of a NimA mutation. (2) The PI proposes to study the role of ubiquitination in the mitotic degradation of NimA. (3) Phosphorylation sites on NimA will be mapped and mutated to determine their role in NimA regulation. (4) The role of NimA in the S phase checkpoint will be explored. Preliminary experiments suggest that inhibition of DNA synthesis may block mitotic entry through inhibition of NimA. The proposed experiments will characterize the control of NimA gene expression by Cdc2 and the control of NimA phosphorylation by BimE, a protein also implicated in NimA control during S phase arrest. (5) Experiments are proposed to further define the precise function of NimA in mitosis, with an emphasis on its role in spindle asembly.