Excision repair of UV-damaged plasmid DNA in Xenopus oocytes is mediated by DNA polymerase α (and/or δ)
Excision repair of UV-damaged plasmid DNA in Xenopus oocytes is mediated by DNA polymerase α (and/or δ)
复制标题
非洲爪蟾卵母细胞中紫外线损伤质粒 DNA 的切除修复是由 DNA 聚合酶 α（和/或 δ）介导的
DOI：
10.1093/nar/18.24.7425
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发表时间：
1990
影响因子：
14.9
通讯作者：
E. Ackerman
中科院分区：
文献类型：
--
作者：
J. Saxena;J. Hays;E. Ackerman
我们研究了DNA修复注射质粒含有随机嘧啶二聚体到非洲爪蟾卵母细胞。我们证明切除修复回收质粒，并与T4紫外核酸内切酶处理和碱性琼脂糖凝胶电泳分析。这些质粒的切除修复机制似乎是进行性的，而不是分配性的，因为修复发生在“全部或无”的方式。在少于4-5个二聚体/质粒时，几乎所有的修复都发生在4-6小时内（每个卵母细胞修复约10（10）个二聚体）;因此，卵母细胞具有丰富的修复活性。特异性抗体和抑制剂用于确定参与修复的酶。我们的结论是，DNA聚合酶α（和/或δ）是必需的，因为修复是由抗体抑制人类DNA聚合酶α，以及aphidicolin，聚合酶α（和/或δ）的抑制剂。修复不受羟基脲、胞嘧啶β-D-阿拉伯呋喃糖苷或拓扑异构酶II抑制剂（新生霉素）的抑制。卵母细胞修复不激活半保守DNA复制，也不需要蛋白质合成。光复活不能解释修复，因为二聚体的去除不依赖于外源光。
We studied DNA repair by injecting plasmids containing random pyrimidine dimers into Xenopus oocytes. We demonstrated excision repair by recovering plasmids and analyzing them with T4 UV endonuclease treatment and alkaline agarose gel electrophoresis. The mechanism for excision repair of these plasmids appears to be processive, rather than distributive, since repair occurs in 'all or none' fashion. At less than 4-5 dimers/plasmid, nearly all repair occurs within 4-6 hours (approximately 10(10) dimers repaired per oocyte); the oocyte, therefore, has abundant repair activity. Specific antibodies and inhibitors were used to determine enzymes involved in repair. We conclude that DNA polymerase alpha (and/or delta) is required because repair is inhibited by antibodies to human DNA polymerase alpha, as well as by aphidicolin, an inhibitor of polymerases alpha (and/or delta). Repair was not inhibited by hydroxyurea, cytosine beta-D-arabinofuranoside, or inhibitors of topoisomerase II (novobiocin). Oocyte repair does not activate semi-conservative DNA replication, nor is protein synthesis required. Photoreactivation cannot account for repair because dimer removal is independent of exogenous light.