Apn1 and Apn2 endonucleases prevent accumulation of repair-associated DNA breaks in budding yeast as revealed by direct chromosomal analysis.
Apn1 and Apn2 endonucleases prevent accumulation of repair-associated DNA breaks in budding yeast as revealed by direct chromosomal analysis.
复制标题
如直接染色体分析所揭示的那样，APN1和APN2核酸内切酶可以防止在发芽的酵母中积累与修复相关的DNA断裂。
DOI：
10.1093/nar/gkm1148
复制
发表时间：
2008-04
影响因子：
14.9
通讯作者：
Gordenin DA
中科院分区：
文献类型：
--
作者：
Ma W;Resnick MA;Gordenin DA
碱基切除修复（BER）可以缓解许多DNA损伤。虽然BER酶已被生物化学表征，但细胞内BER功能的了解要少得多，部分原因是复制旁路和双链断裂（DSB）修复也会影响对碱基损伤的抵抗力。为了研究BER在体内，我们研究了甲基甲磺酸（MMS）诱导的DNA损伤的修复在单倍体G1酵母细胞，使复制旁路和重组DSB修复不能发生。基于MMS诱导的碱基损伤的热不稳定性，开发了监测全长酵母染色体中的次级断裂的测定，其中紧密间隔的断裂产生通过脉冲场凝胶电泳观察到的DSB。该测定检测损坏的碱基和无碱基（AP）位点作为热依赖性断裂以及BER期间出现的中间热不依赖性断裂。使用环状染色体，损伤频率和修复动力学可以很容易地确定。监测BER在单个和多个糖基化酶和AP-核酸内切酶突变体证实，Mag 1是主要的酶，删除MMS损坏的碱基。这种方法提供了直接的物理证据，即Apn 1和Apn 2不仅修复细胞碱基损伤，而且还防止了可能由AP位点被引导到其他BER途径而导致的断裂累积。
Base excision repair (BER) provides relief from many DNA lesions. While BER enzymes have been characterized biochemically, BER functions within cells are much less understood, in part because replication bypass and double-strand break (DSB) repair can also impact resistance to base damage. To investigate BER in vivo, we examined the repair of methyl methanesulfonate (MMS) induced DNA damage in haploid G1 yeast cells, so that replication bypass and recombinational DSB repair cannot occur. Based on the heat-lability of MMS-induced base damage, an assay was developed that monitors secondary breaks in full-length yeast chromosomes where closely spaced breaks yield DSBs that are observed by pulsed-field gel electrophoresis. The assay detects damaged bases and abasic (AP) sites as heat-dependent breaks as well as intermediate heat-independent breaks that arise during BER. Using a circular chromosome, lesion frequency and repair kinetics could be easily determined. Monitoring BER in single and multiple glycosylase and AP-endonuclease mutants confirmed that Mag1 is the major enzyme that removes MMS-damaged bases. This approach provided direct physical evidence that Apn1 and Apn2 not only repair cellular base damage but also prevent break accumulation that can result from AP sites being channeled into other BER pathway(s).
登录
查看更多内容
DOI：
10.1016/0027-5107(90)90173-2
发表时间：
1990-07-01
期刊：
MUTATION RESEARCH
影响因子：
--
作者：
BERANEK, DT
通讯作者：
BERANEK, DT
影响因子：
64.8
作者：
Ira, G;Pellicioli, A;Foiani, M
通讯作者：
Foiani, M
影响因子：
2.9
作者：
LINDAHL, T;ANDERSSON, A
通讯作者：
ANDERSSON, A
影响因子：
3.2
作者：
Memisoglu, A;Samson, L
通讯作者：
Samson, L
影响因子：
2.6
作者：
Jagannathan, I;Cole, HA;Hayes, JJ
通讯作者：
Hayes, JJ