P34CDC2 AND CELL CYCLE CONTROL

在真核生物中，进入有丝分裂是由协同和 不同蛋白激酶级联的相反活性， 磷酸酶 这种级联反应集中在CDC 2，一种丝氨酸/苏氨酸蛋白质上 细胞进入有丝分裂所需的激酶。 两个相邻 CDC 2 N末端内的氨基酸（苏氨酸14和酪氨酸15） 已被证明是调节激酶活性的关键因素 CDC 2的 这些残基的磷酸化可抑制 CDC 2激酶的活性，从而防止细胞进入 分裂。 这项资助的目标是表征激酶， 直接催化或间接调节这些蛋白的磷酸化 关键残留物 编码人和非洲爪蟾Thr 14/Tyr 15激酶的cDNA 将被隔离。 将产生特异性探针，并且每个激酶将 可以在体外和体内进行表征。 此外，上游 将鉴定这些酶的调节剂。 在裂变酵母中， wee 1、nim 1/cdr 1和mik 1基因产物将被研究。 最后 将确定每种激酶的最佳肽基序， 鉴定激酶的潜在底物（除了CDC 2），以及 开发针对每种激酶的特异性肽抑制剂。 这些抑制剂 将用作蛋白质功能的体内探针， 作为设计针对疾病的新药的模板 是由于异常的细胞增殖引起的。

In eukaryotes, entry into mitosis is regulated by the synergistic and opposing activities of a cascade of distinct protein kinases and phosphatases. This cascade converges on CDC2, a serine/threonine protein kinase required for the entry of cells into mitosis. Two neighboring amino acids within the N-terminus of CDC2 (threonine 14 and tyrosine 15) have been shown to be critical elements in regulating the kinase activity of CDC2. Phosphorylation of these residues quantatively inhibits the activity of the CDC2 kinase and thereby prevents cells from entering into mitosis. The goals of this grant are to characterize the kinases that either directly catalyze or indirectly regulate phosphorylation of these key residues. cDNAs encoding the human and Xenopus Thr14/Tyr 15 kinases will be isolated. Specific probes will be generated and each kinase will be characterized both in vitro and in vivo. In addition, upstream regulators of these enzymes will be identified. In fission yeast, the wee1, nim1/cdr1 and mik1 gene products will be studied. Finally, the optimal peptide motif for each kinase will be determined in order to identify potential substrates of the kinases (other that CDC2) and to develop specific peptide inhibitors for each kinase. These inhibitors will be used as in vivo probes of protein function and they may also serve as templates for the design of novel drugs targeted to diseases that arise as a result of aberrant cellular proliferation.