Preferential repair of cyclobutane pyrimidine dimers in the transcribed strand of a gene in yeast chromosomes and plasmids is dependent on transcription.
Preferential repair of cyclobutane pyrimidine dimers in the transcribed strand of a gene in yeast chromosomes and plasmids is dependent on transcription.
复制标题
酵母染色体和质粒中基因转录链中环丁烷嘧啶二聚体的优先修复取决于转录。
DOI：
10.1073/pnas.89.22.10696
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发表时间：
1992
影响因子：
11.1
通讯作者：
Hanawalt,PC
中科院分区：
文献类型：
--
作者：
Sweder,KS;Hanawalt,PC
虽然活性基因内转录链的优先修复已在人类和大肠杆菌等多种生物体中得到证实，但此前尚未表明在酿酒酵母的染色体基因中发生这种情况。我们发现，修复熟练菌株染色体中表达的 RPB2 基因的转录链中环丁烷嘧啶二聚体的修复比非转录链中的修复要快得多。此外，着丝粒 ARS1 质粒上携带的 RPB2 基因的副本在修复中表现出相同的链偏向。为了研究该链偏向与转录的关系，我们研究了 RNA 聚合酶 II 最大亚基中具有温度敏感突变 rpb1-1 的酵母菌株的修复。当呈指数增长的 rpb1-1 细胞转移到不允许的温度时，它们会迅速停止 mRNA 合成。在允许的温度下，rpb1-1和野生型亲本细胞在染色体转录链和质粒携带的RPB2基因拷贝中表现出快速、熟练的修复。在不允许的温度下，rpb1-1 细胞中转录链的修复率降低至非转录链的修复率。这些发现确立了染色体和质粒中 RNA 聚合酶 II 的转录修复中链偏向的依赖性，并验证了使用质粒来分析酵母中修复与转录的关系。
While preferential repair of the transcribed strands within active genes has been demonstrated in organisms as diverse as humans and Escherichia coli, it has not previously been shown to occur in chromosomal genes in the yeast Saccharomyces cerevisiae. We found that repair of cyclobutane pyrimidine dimers in the transcribed strand of the expressed RPB2 gene in the chromosome of a repair-proficient strain is much more rapid than that in the nontranscribed strand. Furthermore, a copy of the RPB2 gene borne on a centromeric ARS1 plasmid showed the same strand bias in repair. To investigate the relation of this strand bias to transcription, we studied repair in a yeast strain with the temperature-sensitive mutation, rpb1-1, in the largest subunit of RNA polymerase II. When exponentially growing rpb1-1 cells are shifted to the nonpermissive temperature, they rapidly cease mRNA synthesis. At the permissive temperature, both rpb1-1 and the wild-type, parental cells exhibited rapid, proficient repair in the transcribed strand of chromosomal and plasmid-borne copies of the RPB2 gene. At the nonpermissive temperature, the rate of repair in the transcribed strand in rpb1-1 cells was reduced to that in the nontranscribed strand. These findings establish the dependence of strand bias in repair on transcription by RNA polymerase II in the chromosomes and in plasmids, and they validate the use of plasmids for analysis of the relation of repair to transcription in yeast.