摘要
目的 探讨人类解旋酶样转录因子（HLTF）转染对辐射诱导细胞凋亡时DNA修复相关蛋白水平的影响.方法 将野生型和RING结构域突变型HLTF分别转染人肺癌细胞A549,60Coγ射线15 Gy照射诱导细胞凋亡,用Western blot检测HRAD17和HRAD52蛋白水平的变化,免疫共沉淀检测特定复合物的存在.结果 γ射线诱导细胞凋亡时,野生型HLTF转染组与对照组相比,DNA修复蛋白HRAD17和HRAD52水平明显降低,而RING结构域突变组与对照组相比则没有明显变化;辐射诱导细胞凋亡时,HLTF可与HRAD17和HRAD52形成复合物.结论 HLTF可介导辐射诱导的凋亡细胞中HRAD17和HRAD52的降解,其机制可能是通过蛋白质复合物的相互作用使DNA修复蛋白泛素化而降解.
Objective To study the effects of helicase-like transcription factor （HLTF）transfection on DNA repair protein level in radiation-induced apoptotic cells.Methods Human lung carcinoma A549 cells were cultured and transfected with FLAG-tagged wild type HLTF （wild type HLTF transfection group）,RING structure domain （ubiquitin conjugating region） mutatation HLTF expressing plasmid （mutant transfection group）,empty plasmid （congtrol group） respectively.And the other cells were used as mock transfection group.All cells were irradiated with 15 Gy of 60Co γ-rays to induce apoptosis.Western blotting was used to detect the protein levels of the DNA repair proteins HRAD17 and HRAD52 in the transfected cells.Results The levels of HRAD17 and HRAD52 in the wild type HLTF transfection group was significantly lower than that of the control group.There was no significant difference in HRAD17 and HRAD52 levels between the mock transfection group and ubiquity in conjugating region mutation group.complexes of HLTF and HRAD17 and HRAD52 could be found in the irradiation-induced cells.Conclusions HLTF mediates the degradation of HRAD17 and HRAD52 in the irradiation-induced apoptotic cells possibly by the interaction of the protein complex causing ubiquitination of the repair proteins.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2010年第5期510-512,共3页
Chinese Journal of Radiological Medicine and Protection
基金
国家自然科学基金（30470976）
关键词
细胞凋亡
HLTF
RING结构域
Apoptosis
Helicase-like transcription factor （HLTF）
RING domain
