The yeast Saccharomyces cerevisiae DNA polymerase IV: possible involvement in double strand break DNA repair.
The yeast Saccharomyces cerevisiae DNA polymerase IV: possible involvement in double strand break DNA repair.
复制标题
酿酒酵母 DNA 聚合酶 IV：可能参与双链断裂 DNA 修复。
DOI：
10.1093/nar/22.15.3011
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发表时间：
1994
影响因子：
14.9
通讯作者：
A. Sugino
中科院分区：
文献类型：
--
作者：
S. Leem;P. Ropp;A. Sugino
我们鉴定并纯化了一种新的DNA聚合酶（DNA聚合酶IV），它类似于哺乳动物的DNA聚合酶β，从酿酒酵母，并建议它是由染色体III上的YCR 14 C（POLX）编码。在这里，我们提供了一个直接的证据，纯化的DNA聚合酶IV确实是由POLX编码。携带pol4缺失突变的菌株既不表现出有丝分裂生长缺陷，也不表现出减数分裂缺陷，这表明DNA聚合酶IV参与了DNA代谢中的非必需功能。缺失菌株没有表现出UV敏感性。然而，它们确实显示出对MMS处理的弱敏感性，并且当在减数分裂期间测量基因内重组时表现出超重组表型。此外，MAT α pol4 δ分离子与MAT α测试菌株的非法交配频率高于野生型细胞。这些结果表明，DNA聚合酶IV参与了双链断裂修复途径。在有丝分裂生长的细胞中弱表达3.2kb的POL4转录物。在减数分裂过程中，2.2kb的POL4转录物被大量诱导，而3.2kb的转录物保持在恒定水平。在减数分裂期间，这种诱导在swi4 δ菌株中被延迟，而在swi6 δ菌株中没有观察到效果。
We identified and purified a new DNA polymerase (DNA polymerase IV), which is similar to mammalian DNA polymerase beta, from Saccharomyces cerevisiae and suggested that it is encoded by YCR14C (POLX) on chromosome III. Here, we provided a direct evidence that the purified DNA polymerase IV is indeed encoded by POLX. Strains harboring a pol4 deletion mutation exhibit neither mitotic growth defect nor a meiosis defect, suggesting that DNA polymerase IV participates in nonessential functions in DNA metabolism. The deletion strains did not exhibit UV-sensitivity. However, they did show weak sensitivity to MMS-treatment and exhibited a hyper-recombination phenotype when intragenic recombination was measured during meiosis. Furthermore, MAT alpha pol4 delta segregants had a higher frequency of illegitimate mating with a MAT alpha tester strain than that of wild-type cells. These results suggest that DNA polymerase IV participates in a double-strand break repair pathway. A 3.2kb of the POL4 transcript was weakly expressed in mitotically growing cells. During meiosis, a 2.2 kb POL4 transcript was greatly induced, while the 3.2 kb transcript stayed at constant levels. This induction was delayed in a swi4 delta strain during meiosis, while no effect was observed in a swi6 delta strain.