Dosage suppressors of pds1 implicate ubiquitin-associated domains in checkpoint control
Dosage suppressors of pds1 implicate ubiquitin-associated domains in checkpoint control
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DOI：
10.1128/mcb.21.6.1997-2007.2001
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发表时间：
2001-03-01
影响因子：
5.3
通讯作者：
Reed, SI
中科院分区：
文献类型：
--
作者：
Clarke, DJ;Mondesert, G;Reed, SI
在芽殖酵母中，后期的启动是由依赖泛素的Pds1p的降解控制的，pds1突变体的分析表明Pds1p参与了DNA损伤、纺锤体组装和S相检查点。虽然这些途径的一些组成部分已知，但其他成分仍有待确定。此外，Pds1p的基本功能与其在检查站控制中的作用无关，尚未阐明。为了确定与PDS1基因相互作用的基因座，我们筛选了对温度敏感的PDS1等位基因pds1-128的剂量抑制因子，该等位基因在允许的温度下对检查点控制有缺陷，在37℃下对生存至关重要。RAD23和DDI1能抑制温度和羟基脲，但不能抑制辐射和诺唑醇。突变体PDS1-128、RAD23和DDi1对S期检查点控制的敏感性存在部分缺陷，但擅长DNA损伤和纺锤体组装检查点。因此，Rad23p和Ddi1p参与了Pds1p依赖的细胞周期调控的一个子集。Rad23p和Ddi1p都含有泛素相关(UBA)结构域，这是剂量抑制PDS1-128所必需的。UBA结构域存在于几个参与泛素依赖蛋白分解的蛋白质中，尽管它们的功能尚未被赋予。RAD23p和Ddi1p的UBA结构域的缺失导致细胞在S期检查点调控中存在缺陷，这意味着UBA结构域参与了检查点信号转导。由于Pds1p的破坏，从而有丝分裂的检查点调节，依赖于泛素依赖的蛋白分解，我们认为UBA结构域与泛素系统在功能上相互作用，以控制Pds1p的降解，以响应检查点激活。
In budding yeast, anaphase initiation is controlled by ubiquitin-dependent degradation of Pds1p, Analysis of pds1 mutants implicated Pds1p in the DNA damage, spindle assembly, and S-phase checkpoints. Though some components of these pathways are known, others remain to be identified. Moreover, the essential function of Pds1p, independent of its role in checkpoint control, has not been elucidated. To identify loci that genetically interact with PDS1, we screened for dosage suppressors of a temperature-sensitive pds1 allele, pds1-128, defective for checkpoint control at the permissive temperature and essential for viability at 37 degreesC. Genetic and functional interactions of two suppressors are described, RAD23 and DDI1 suppress the temperature and hydroxyurea, but not radiation or nocodazole, sensitivity of pds1-128, rad23 and ddi1 mutants are partially defective in S-phase checkpoint control but are proficient in DNA damage and spindle assembly checkpoints. Therefore, Rad23p and Ddi1p participate in a subset of Pds1p-dependent cell cycle controls. Both Rad23p and Ddi1p contain ubiquitin-associated (UBA) domains which are required for dosage suppression of pds1-128, UBA domains are found in several proteins involved in ubiquitin-dependent proteolysis, though no function has been assigned to them. Deletion of the UBA domains of Rad23p and Ddi1p renders cells defective in S-phase checkpoint control, implicating UBA domains in checkpoint signaling. Since Pds1p destruction, and thus checkpoint regulation of mitosis, depends on ubiquitin-dependent proteolysis, we propose that the UBA domains functionally interact with the ubiquitin system to control Pds1p degradation in response to checkpoint activation.