Verde F, Wiley D J, Nurse P
Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, P.O. Box 016129, Miami, FL, 33101-6129, USA.
Proc Natl Acad Sci U S A. 1998 Jun 23;95(13):7526-31. doi: 10.1073/pnas.95.13.7526.
The molecular mechanisms that coordinate cell morphogenesis with the cell cycle remain largely unknown. We have investigated this process in fission yeast where changes in polarized cell growth are coupled with cell cycle progression. The orb6 gene is required during interphase to maintain cell polarity and encodes a serine/threonine protein kinase, belonging to the myotonic dystrophy kinase/cot1/warts family. A decrease in Orb6 protein levels leads to loss of polarized cell shape and to mitotic advance, whereas an increase in Orb6 levels maintains polarized growth and delays mitosis by affecting the p34(cdc2) mitotic kinase. Thus the Orb6 protein kinase coordinates maintenance of cell polarity during interphase with the onset of mitosis. orb6 interacts genetically with orb2, which encodes the Pak1/Shk1 protein kinase, a component of the Ras1 and Cdc42-dependent signaling pathway. Our results suggest that Orb6 may act downstream of Pak1/Shk1, forming part of a pathway coordinating cell morphogenesis with progression through the cell cycle.
协调细胞形态发生与细胞周期的分子机制在很大程度上仍然未知。我们在裂殖酵母中研究了这一过程，其中极化细胞生长的变化与细胞周期进程相关联。orb6基因在间期是维持细胞极性所必需的，它编码一种丝氨酸/苏氨酸蛋白激酶，属于强直性肌营养不良激酶/cot1/warts家族。Orb6蛋白水平的降低会导致极化细胞形态的丧失和有丝分裂的提前，而Orb6水平的增加则通过影响p34(cdc2)有丝分裂激酶来维持极化生长并延迟有丝分裂。因此，Orb6蛋白激酶在间期协调细胞极性的维持与有丝分裂的开始。orb6与orb2发生遗传相互作用，orb2编码Pak1/Shk1蛋白激酶，它是Ras1和Cdc42依赖性信号通路的一个组成部分。我们的结果表明，Orb6可能在Pak1/Shk1的下游起作用，形成协调细胞形态发生与细胞周期进程的一条通路的一部分。
