Ribar Balazs, Prakash Louise, Prakash Satya
Sealy Center for Molecular Science, University of Texas Medical Branch at Galveston, Galveston, TX 77555-1061, USA.
Mol Cell Biol. 2006 Jun;26(11):3999-4005. doi: 10.1128/MCB.00293-06.
Treatment of Saccharomyces cerevisiae and human cells with DNA-damaging agents such as UV light or 4-nitroquinoline-1-oxide induces polyubiquitylation of the largest RNA polymerase II (Pol II) subunit, Rpb1, which results in rapid Pol II degradation by the proteasome. Here we identify a novel role for the yeast Elc1 protein in mediating Pol II polyubiquitylation and degradation in DNA-damaged yeast cells and propose the involvement of a ubiquitin ligase, of which Elc1 is a component, in this process. In addition, we present genetic evidence for a possible involvement of Elc1 in Rad7-Rad16-dependent nucleotide excision repair (NER) of lesions from the nontranscribed regions of the genome and suggest a role for Elc1 in increasing the proficiency of repair of nontranscribed DNA, where as a component of the Rad7-Rad16-Elc1 ubiquitin ligase, it would promote the efficient turnover of the NER ensemble from the lesion site in a Rad23-19S proteasomal complex-dependent reaction.
用紫外线或4-硝基喹啉-1-氧化物等DNA损伤剂处理酿酒酵母和人类细胞，会诱导最大的RNA聚合酶II（Pol II）亚基Rpb1发生多聚泛素化，进而导致Pol II被蛋白酶体快速降解。我们在此确定了酵母Elc1蛋白在介导DNA损伤的酵母细胞中Pol II多聚泛素化和降解过程中的新作用，并提出在此过程中有一种泛素连接酶（Elc1是其组成部分）参与其中。此外，我们提供了遗传学证据，表明Elc1可能参与了基因组非转录区域损伤的Rad7-Rad16依赖性核苷酸切除修复（NER），并提出Elc1在提高非转录DNA修复效率中发挥作用，作为Rad7-Rad16-Elc1泛素连接酶的组成部分，它会在依赖Rad23-19S蛋白酶体复合物的反应中促进NER组件从损伤位点的有效周转。
