一种与HeLa细胞紫外线抗性相关的体外紫外线损伤识别因子的特性分析。

Characterization of a UV-damage recognition factor in vitro that is associated with UV resistance in HeLa cells.

作者信息

Chao C C

机构信息

Department of Biochemistry, Chang Gung Medical College, Taoyuan, Taiwan.

出版信息

Mutat Res. 1992 Feb;281(2):105-13. doi: 10.1016/0165-7992(92)90044-i.

DOI:10.1016/0165-7992(92)90044-i

PMID:1370977

Abstract

We have previously reported a cisplatin-selected HeLa cell line showing cross-resistance to ultraviolet (UV) radiation and overexpression of UV-damage recognition factors (Chao et al., Mol. Cell. Biol., 11, 2075-2080, 1991). Here, we further characterize a UV-damage recognition factor in vitro using a gel mobility shift assay. The results indicate that the damage-recognition factor is (i) localized mostly in the nucleus, (ii) protease-sensitive, (iii) RNA-independent, (iv) active in a wide range of ionic strengths (50-400 mM NaCl), (v) with a high affinity for UV-damaged DNA (50-fold molar excess competitor causes 50% recognition loss), and (vi) resistant to agents and that modify protein conformation (urea and NP-40), but slightly sensitive to CaCl2. The significance of the identified UV-damage recognition factor in the sensitivity or resistance of cells to UV is also discussed.

摘要

我们之前报道过一种经顺铂筛选的HeLa细胞系，该细胞系对紫外线（UV）辐射表现出交叉抗性，且紫外线损伤识别因子过表达（Chao等人，《分子与细胞生物学》，第11卷，2075 - 2080页，1991年）。在此，我们使用凝胶迁移率变动分析在体外进一步表征一种紫外线损伤识别因子。结果表明，损伤识别因子具有以下特点：（i）主要定位于细胞核；（ii）对蛋白酶敏感；（iii）不依赖RNA；（iv）在广泛的离子强度范围（50 - 400 mM NaCl）内具有活性；（v）对紫外线损伤的DNA具有高亲和力（50倍摩尔过量的竞争者导致50%的识别丧失）；以及（vi）对改变蛋白质构象的试剂（尿素和NP - 40）具有抗性，但对CaCl2略有敏感。我们还讨论了所鉴定的紫外线损伤识别因子在细胞对紫外线的敏感性或抗性中的意义。