CHARACTERIZATION OF A CELL DIVISION CONTROL RELATED GENE

细胞通过细胞分裂进行繁殖的能力是最大的 所有生命物质的基本过程。这些异常现象 转化细胞的生长过程往往与过程有关。因此， 对正常细胞分裂所涉及的事件的彻底理解是 对于理解转化细胞的生长至关重要。为此，有几个 研究小组已经确定了一种细胞分裂控制蛋白激酶p34cdc2， 这是正常有丝分裂的关键组成部分。去除这种蛋白质 最近的研究表明，有丝分裂中的激酶活性被阻断。 然而，这个系统是复杂的，激活这个激酶的蛋白质， 以及那些由这种激酶活性作用的基因，仍然存在 身份不明。我们已经确定了一种新的蛋白激酶，它高度 与p34cdc2激酶有68%的同源性。这种新的激酶是394个氨基酸。 酸的大小，显然是由磷酸化和钙离子- 钙调蛋白，定位于细胞质和胞核。的表达 相应的信使核糖核酸在细胞周期中被调节，在 G(1)-和S-阶段。CDC相关蛋白的高表达 真核细胞导致细胞周期在晚期明显受阻。 末期与早期G(1)分界。我们建议在分子水平上研究 和生化水平，这种CDC相关的激酶的性质和作用 在细胞周期控制中。这将通过检查其 细胞周期中的调节。仔细分析稳态信使核糖核酸和 蛋白质水平、激酶活性、磷酸化状态和蛋白质-蛋白质 作为细胞周期函数的相互作用将使用cDNA 这一新的CDC相关蛋白的克隆和抗体。我们还将检查 CDC相关基因的转录和转录后调控 信使核糖核酸作为细胞周期的函数。杂交数据表明 人类和小鼠体内存在与序列相关的转录本。这些序列将 进行分离和测序，以确定是否存在更大的基因家族。 最后，这种新的CDC相关激酶的结构/功能将是 通过缺失和定点突变以及表达来检查 在真核细胞中。这些研究将最终确定 这种CDC相关的激酶在正常和转化的细胞生长中都是 对于理解细胞分裂控制的分子基础至关重要。

The ability of a cell to reproduce by cell division is one of the most fundamental processes of all living matter. Abnormalities of these processes are often involved in the growth of transformed cells. Therefore, a thorough understanding of the events involved in normal cell division is crucial to understanding transformed cell growth. To this end several groups have identified a cell division control protein kinase, p34cdc2, that is a crucial component of normal mitosis. Removal of this protein kinase activity has recently been shown to lead to a block in mitosis. However, this system is complex and the proteins that activate this kinase, as well as those that are acted upon by this kinase activity, remain unidentified. We have identified a new protein kinase that is highly related (68% homology) to the p34cdc2 kinase. This new kinase is 394 amino acids in size, is apparently regulated by phosphorylation and Ca2+ - calmodulin, and is localized to the cytoplasm and nucleus. Expression of the corresponding mRNA is regulated during the cell cycle, peaking during G(1)-and S-phase. Elevated expression of this CDC-related kinase in eukaryotic cells leads to an apparent block of the cell cycle at the late telophase and early G(1) boundary. We propose to examine, at a molecular and biochemical level, the nature of this CDC-related kinase and its role in cell cycle control. This will be accomplished by examining its regulation during the cell cycle. Careful analysis of steady-state mRNA and protein levels, kinase activity, phosphorylation state, and protein-protein interactions as a function of cell cycle will be performed using cDNA clones and antibodies for this new CDC-related kinase.We will also examine transcriptional and post-transcriptional regulation of the CDC-related mRNA as a function of cell cycle. Hybridization data indicates that sequence-related transcripts exist in humans and mice. These sequences will be isolated and sequenced to determine whether a larger gene family exists. Finally, the structure/function of this new CDC-related kinase will be examined by deletion and site-specific mutagenesis, as well as expression in eukaryotic cells. These studies will ultimately define the role of this CDC-related kinase in both normal and transformed cell growth, and are essential for understanding the molecular basis of cell division control.