哺乳动物DNA核酸切除修复与纯化的蛋白质成分复制
A Aboussekhra1, M Biggerstaff, M K Shivji
1Imperial Cancer Research Fund, Clare Hall Laboratoires, South Mimms, Herts, England.
Cell
|March 24, 1995
概括
人类细胞使用核酸切除修复来修复UVDNA损伤. 研究人员使用纯化蛋白质重建了这种修复过程,确定了DNA修复合成的基本组件.
科学领域:
- 分子生物学分子生物学
- DNA 修复机制的修复机制
- 人类遗传学 人类遗传学
背景情况:
- 核酸切除修复 (NER) 对于消除人类细胞中紫外线诱导的DNA损伤至关重要.
- 在NER中存在的缺陷与色素脱皮症 (XP) 相关,这种疾病的特征是极度敏感于阳光.
- 确定涉及NER的特定蛋白质因素对于理解DNA修复和相关疾病至关重要.
研究的目的:
- 识别和重组参与人类核酸切除修复的关键蛋白质成分.
- 描述DNA切割和紫外线损伤后修复合成的原因.
- 为了研究色素 (XP) 和ERCC因子在NER途径中的作用.
主要方法:
- 人体细胞提取物的分化,以分离活性NER成分.
- 使用包括RPA,XPA,TFIIH,XPC,UV-DDB,XPG和ERCC1/XPF复合体在内的净化蛋白质进行DNA切口反应的复合.
- 一种与ERCC1/XPF活性相关的新型110 kDa多的表征.
- 使用纯化的NER因子,DNA聚合酶epsilon,RFC,PCNA和DNA结合酶I进行完整修复合成的重构.
主要成果:
- 切口反应被用大约30种多复制,包括RPA,XPA,TFIIH (XPB,XPD),XPC,XPG和ERCC1/XPF复合体.
- 发现UV-DDB (XPE) 刺激但对修复过程没有必要.
- 在XP-F细胞中缺少的一种110kDa的多被识别并与ERCC1/XPF纠正活性共净化.
- 通过重建的系统实现了完整的DNA修复合成.
结论:
- 该研究成功地重建了核心人类核酸切除修复途径,涉及约30种蛋白质.
- 与ERCC1/XPF相关的新型110 kDa因子对NER至关重要,它的缺失解释了XP-F.
- 这种重建的系统为进一步剖析DNA修复机制和识别与疾病相关的因素提供了强大的工具.
相关概念视频
Nucleotide Excision Repair
Overview
Base Excision Repair
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
The first step of...
Nucleotide Excision Repair
Overview
Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
Base Excision Repair
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
The first step of...
Nucleotide Excision Repair
DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...


