Excision repair of ultraviolet damage in mammalian cells. Evidence for two steps in the excision of pyrimidine dimers.
Excision repair of ultraviolet damage in mammalian cells. Evidence for two steps in the excision of pyrimidine dimers.
复制标题
哺乳动物细胞紫外线损伤的切除修复。
DOI：
10.1016/s0006-3495(78)85488-5
复制
发表时间：
1978
影响因子：
3.4
通讯作者：
J. Cleaver
中科院分区：
文献类型：
--
作者：
J. Williams;J. Cleaver
通过测量存活率、T4内切核酸酶V敏感位点、酸不溶性DNA中嘧啶二聚体的分数（薄层层析法（TLC）测定）和修复复制，研究了紫外线（UV）照射后非洲绿色猴肾CV-1细胞中嘧啶二聚体形成的发生率和DNA修复动力学。CV-1细胞显示存活曲线，外推数n=7.8，Do=2.5 J/m2。嘧啶二聚体从酸不溶性DNA中丢失的速度比核酸内切酶敏感位点丢失的速度慢，或者在修复过程中将新的碱基掺入高分子量DNA中。CV-1培养物在[3 H]胸苷或X射线照射（2或10 krad）24小时前UV照射的生长对25 J/m2的UV诱导的修复复制没有影响。这些结果表明，嘧啶二聚体切除测量TLC可能不受辐射从高水平的纳入放射性核素。核酸内切酶敏感位点和TLC测量可以通过以下假设来调和：嘧啶二聚体从酸不溶性寡核苷酸中的高分子量DNA中切除，所述酸不溶性寡核苷酸缓慢降解为酸溶性片段。
The incidence of pyrimidine dimer formation and the kinetics of DNA repair in African green monkey kidney CV-1 cells after ultraviolet (UV) irradiation were studied by measuring survival, T4 endonuclease V-sensitive sites, the fraction of pyrimidine dimers in acid-insoluble DNA as determined by thin layer chromatography (TLC), and repair replication. CV-1 cells exhibit a survival curve with extrapolation number n=7.8 and Do=2.5 J/m2. Pyrimidine dimers were lost from acid-insoluble DNA more slowly than endonuclease-sensitive sites were lost from or new bases were incorporated into high molecular weight DNA during the course of repair. Growth of CV-1 cultures in [3H]thymidine or X-irradiation (2 or 10 krads) 24 h before UV irradiation had no effect on repair replication induced by 25 J/m2 of UV. These results suggest that pyrimidine dimer excision measurements by TLC are probably unaffected by radiation from high levels of incorporated radionuclides. The endonuclease-sensitive site and TLC measurements can be reconciled by the assumption that pyrimidine dimers are excised from high molecular weight DNA in acid-insoluble oligonucleotides that are slowly degraded to acid-soluble fragments.