ZDS2P REGULATES SWE1P-DEPENDENT POLARIZED CELL GROWTH IN S CEREVISIAE

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 在发芽酵母中ZDS1和ZDS2的缺失导致了极化细胞生长的错误调节。在这里，我们展示了这些基因作为调节Swe1p(Wee1p)激酶依赖的G2/M检查点的功能。我们在Zds2p的C末端发现了一个由813-912氨基酸组成的保守结构域(以下称为ZDS同源4的ZH4)，它是调节依赖Swe1p的极化芽生长所必需的。蛋白质亲和力分析表明，ZH4是与蛋白磷酸酶2A(PP2A)的调节亚基CDC55P相互作用的必要条件和充分条件。我们假设ZDS蛋白通过CDC55P对Swe1p依赖的G2/M检查点进行负向调节。支持这一模型的是，CDC55的缺失挽救了一株菌株的异常芽形态。我们还发现，即使当依赖Swe1p的G2/M检查点被肌动蛋白细胞骨架的错误组织激活时，来自半乳糖诱导的强启动子的ZDS1或ZDS2的表达也可以诱导有丝分裂。这种负调控需要CDC55基因。综上所述，这些数据表明，CDC55p/Zds2p模块在调节依赖Swe1p的G2/M检查点方面具有功能。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Deletion of the paralogs ZDS1 and ZDS2 in the budding yeast Saccharomyces cerevisiae causes a mis-regulation of polarized cell growth. Here we show a function for these genes as regulators of the Swe1p (Wee1p) kinase-dependent G2/M checkpoint. We identified a conserved domain in the C-terminus of Zds2p consisting of amino acids 813-912 (hereafter referred to as ZH4 for Zds homology 4) that is required for regulation of Swe1p-dependent polarized bud growth. ZH4 is shown by protein affinity assays to be necessary and sufficient for interaction with Cdc55p, a regulatory subunit of protein phosphatase 2A (PP2A). We hypothesized that the Zds proteins are in a pathway that negatively regulates the Swe1p-dependent G2/M checkpoint via Cdc55p. Supporting this model, deletion of CDC55 rescues the aberrant bud morphology of a zds1Δzds2Δ strain. We also show that expression of ZDS1 or ZDS2 from a strong galactose-inducible promoter can induce mitosis even when the Swe1p-dependent G2/M checkpoint is activated by mis-organization of the actin cytoskeleton. This negative regulation requires the CDC55 gene. Together these data indicate that the Cdc55p/Zds2p module has a function in the regulation of the Swe1p-dependent G2/M checkpoint.