Fournier N, Cerutti L, Beltraminelli N, Salimova E, Simanis V
Cell Cycle Control Laboratory, ISREC, Epalinges, Switzerland.
Arch Microbiol. 2001 Jan;175(1):62-9. doi: 10.1007/s002030000238.
The onset of septum formation in the fission yeast Schizosaccharomyces pombe is signaled via the spglp GTPase-switch, which is part of the septation initiation network. This is negatively regulated by the two-component GTPase-activating protein (GAP) comprised of the products of the cdc16 and byr4 genes. Loss-of-function mutations in either of these genes result in multiple rounds of septum formation without cell cleavage. In this work, we demonstrate that attenuation of the protein kinase cdc7p can rescue the lethality of a null allele of cdc16. This observation provides the basis for selection of chromosomal mutations and multicopy suppressors that attenuate the signaling of septation. Using this screen, mutations in all the previously described septation initiation network genes were obtained, with the exception of byr4, sid4 and plo1. We also demonstrate that increased expression of the dma1 gene can rescue the lethality of a null allele of cdc16. The implications for the regulation of septum formation in fission yeast are discussed.
在裂殖酵母粟酒裂殖酵母中，隔膜形成的起始是通过spglp GTP酶开关发出信号的，该开关是隔膜起始网络的一部分。它受到由cdc16和byr4基因产物组成的双组分GTP酶激活蛋白（GAP）的负调控。这两个基因中任何一个的功能丧失突变都会导致在没有细胞分裂的情况下进行多轮隔膜形成。在这项工作中，我们证明蛋白激酶cdc7p的减弱可以挽救cdc16无效等位基因的致死性。这一观察结果为选择减弱隔膜信号传导的染色体突变和多拷贝抑制子提供了基础。利用这个筛选方法，除了byr4、sid4和plo1之外，获得了所有先前描述的隔膜起始网络基因的突变。我们还证明dma1基因表达的增加可以挽救cdc16无效等位基因的致死性。文中讨论了对裂殖酵母中隔膜形成调控的影响。
