NIMA PROTEIN KINASE IN MITOTIC REGULATION

描述：拟议的实验旨在延续PI的 丝状真菌曲霉NIMA蛋白激酶的研究 尼杜兰。之前的工作，几乎完全来自PI的实验室， 证明了NIMA是通过有丝分裂所必需的，并且是 受涉及磷酸化和降解的复杂机制调节。 有一些证据表明，在其他真核生物中存在nimA同源物。 这种激酶在真核生物的控制中通常是重要的 有丝分裂。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。确实有 五个具体目标：(1)利用遗传和生化方法 识别与NIMA相互作用的蛋白质。已经取得了重大进展 对Sona的特征进行了研究，Sona是一种外源抑制基因 尼玛突变。(2)国际和平研究所建议研究泛素化在 NIMA的有丝分裂降解。(3)NIMA上的磷酸化位点将是 定位和突变以确定它们在NIMA调控中的作用。(4)角色 将探索尼玛在S阶段的检查站。初步实验 提示抑制DNA合成可能通过阻止有丝分裂进入 NIMA的抑制作用。拟议中的实验将描述控制的特征 Cdc2对NimA基因表达的影响及其对NimA磷酸化的调控 BimE是一种蛋白质，在S的细胞周期停滞期间也参与了NIMA的控制。(5) 提出了进一步定义NIMA的精确功能的实验方案 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.