细胞裂解物系统中的非程序性DNA合成反映了体内的DNA修复。

Unscheduled DNA synthesis in cell lysate system reflecting DNA repair in vivo.

作者信息

Yamada K, Hanaoka F, Kato H, Yamada M

出版信息

Cell Struct Funct. 1984 Dec;9(4):327-36. doi: 10.1247/csf.9.327.

DOI:10.1247/csf.9.327

Abstract

A cell lysate system by which DNA repair (unscheduled) synthesis induced by DNA damaging agents can be measured at high sensitivity as previously reported (9, 18) was characterized. Time-course experiments in which the in vivo incubation time with hydroxyurea and arabinofuranosyl cytosine after UV irradiation was changed suggested that the number of single strand gaps increased in the presence of these drugs. Alkaline sucrose density gradient analysis of prelabeled DNA revealed that the repair apparatus in the drug-treated cells was not irreversibly impaired. Product DNA in this lysate system was compared with that of an in vitro replication system on alkaline CsC1 equilibrium density gradient, and the results showed that DNA synthesis in the lysate system was "repair-type" synthesis. When the cells were labeled with 5-bromo-2'-deoxyuridine (BrdUrd) in vivo and then labeled with [3H] dTTP in vitro, the photolysis of BrdUrd-labeled DNA decreased the molecular weight, indicating that DNA synthesis in the cell lysate was a continuation of DNA repair in vivo.

摘要

一种细胞裂解物系统被进行了特性描述，通过该系统，如先前报道（9, 18）那样，可以高灵敏度地检测由DNA损伤剂诱导的DNA修复（非预定）合成。紫外线照射后，改变与羟基脲和阿糖胞苷的体内孵育时间的时间进程实验表明，在这些药物存在的情况下，单链缺口的数量增加。对预标记DNA的碱性蔗糖密度梯度分析表明，药物处理细胞中的修复装置并未受到不可逆的损害。在碱性CsC1平衡密度梯度上，将该裂解物系统中的产物DNA与体外复制系统的产物DNA进行比较，结果表明裂解物系统中的DNA合成是“修复型”合成。当细胞在体内用5-溴-2'-脱氧尿苷（BrdUrd）标记，然后在体外用[3H] dTTP标记时，BrdUrd标记DNA的光解降低了分子量，这表明细胞裂解物中的DNA合成是体内DNA修复的延续。