Signaling Pathways and Microtubule Function

描述（由申请人提供）：我们的长期目标是了解细胞中的信号通路如何控制微管的特性。具体来说，我们将集中在可能的作用，蛋白激酶C（PKC）介导的丝裂原活化蛋白激酶（MAPK）和Cdc42pICdc24p途径在控制微管稳定性。我们的工作假设是基于初步研究，其中我们确定了两个基因参与这些途径作为多拷贝抑制剂的后期马达蛋白Cin8和Dyn1的突变。这些基因是KRE6，据报道，KRE6可以抑制pkc1（酵母PKC同源物）和GIC1（Cdc42p的效应子）的裂解表型。在其他初步实验中，我们发现这些抑制因子可能通过稳定微管起作用。我们的具体目标将是（1）确定与这些途径相关的其他抑制因子，（2）表征抑制因子对微管功能的影响，以及（3）研究微管功能与上述途径之间的关系。对于目标1，我们将继续研究我们以前分离的抑制克隆。目的二是研究在抑制因子作用下细胞质和细胞核微管的结构和功能。在目标3中，我们将使用遗传学方法来研究与上述途径相关的基因突变和过度表达对微管特性的影响。该项目取得的成果将在两个方面提供新的重要信息。首先，他们将展示如何保守的信号机制，调节极化生长和各种皮质事件影响微管依赖的过程。其次，他们将展示这些途径如何相互作用。

DESCRIPTION (provided by applicant): Our long-term goal is to understand how signaling pathways in the cell control properties of microtubules. Specifically, we will concentrate on possible roles of the protein kinase C (PKC)-mediated mitogen activated protein kinase (MAPK) and the Cdc42pICdc24p pathways in controlling microtubule stability. Our working hypothesis is based on preliminary studies in which we identified two genes involved in these pathways as multicopy suppressors of mutations in the anaphase motor proteins Cin8 and Dyn1. The genes are KRE6 that was reported to suppress the lysis phenotype of pkc1, the yeast PKC homolog, and GIC1, an effector of Cdc42p. In other preliminary experiments, we found that these suppressors may act by stabilizing microtubules. Our specific aims will be (1) to identify additional suppressors related to these pathways, (2) to characterize the effect of the suppressors on microtubule function, and (3) to study the relation between microtubule function and the above pathways. For aim 1 we will continue to investigate suppressor clones that we previously isolated. In aim 2 we will study organization and function of cytoplasmic and nuclear microtubules under the effect of the suppressors. In aim 3 we will use a genetic approach to investigate the effect of mutations in, and overexpression of, genes related to the above pathways on microtubule properties. Results obtained in this project will provide new and important information in two contexts. First, they will show how conserved signaling mechanisms that regulate polarized growth and a variety of cortical events affect microtubule--dependent processes. Second, they will show how these pathways interact.