对慢性低剂量紫外线的RAD6-RAD18-RAD5通路依赖的耐受性
Takashi Hishida1, Yoshino Kubota, Antony M Carr
1Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan. hishida@biken.osaka-u.ac.jp
Nature
|December 17, 2008
概括
慢性低剂量紫外线照射突出了RAD6无错误后复制修复途径在酵母细胞生存和繁殖中的关键作用. 这种途径可以防止DNA损伤检查点的激活,确保正常的细胞生长.
科学领域:
- 细胞生物学 细胞生物学
- 分子遗传学 分子遗传学
- DNA 修复机制的修复机制
背景情况:
- 有机体在自然界面临慢性低剂量紫外线 (CLUV) 暴露,与急性高剂量实验室条件不同.
- 急性紫外线暴露主要涉及核酸切除修复和细胞循环停止的生存.
- 对CLUV的细胞反应仍然不太了解.
研究的目的:
- 为了研究酵母细胞对慢性低剂量紫外线 (CLUV) 的反应.
- 确定参与CLUV生存的关键DNA修复途径.
- 阐明RAD6-RAD18-RAD5无错误复制后修复 (PRR) 途径的作用.
主要方法:
- 酵母细胞暴露于CLUV.
- 细胞周期进展和DNA损伤检查点的分析.
- 对DNA修复途径突变的评估 (例如,rad18Δ).
- 对复制蛋白A (RPA) 和Rad52焦点的观察.
主要成果:
- 在暴露于CLUV的细胞中,RAD6无错误的PRR通路的损失会导致G2停止.
- 这次停产并不是由于维修缺陷或光电产品积累.
- 通过Rad52介导的同源重组对于在Rad18Δ细胞中停留后的活力至关重要.
- 在CLUV暴露的rad18Δ细胞中观察到增加的RPA和Rad52焦点.
结论:
- 在CLUV下,无错误的RAD6PRR通路对于促进细胞生长和存活至关重要.
- 这种途径可以促进受损DNA的复制,而不需要大量的单链DNA形成.
- 无错误的PRR可以防止有害的DNA检查点激活,使慢性紫外线暴露期间的正常增殖成为可能.
相关概念视频
01:08Nucleotide Excision Repair
40.4K
Overview
40.4K
01:39Mutations
94.1K
Overview
94.1K
02:36DNA Damage can Stall the Cell Cycle
9.9K
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
9.9K
01:35Mutations
42.5K
Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations can be characterized in a number of different ways: whether and how they alter the amino acid sequence of the protein, whether they occur over a small or large area of DNA, and whether they occur in somatic cells or germline cells.
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
42.5K
01:38Nucleotide Excision Repair
4.8K
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...
4.8K
01:18Other Unique Bacteria
322
Magnetic bacteria exhibit a directed movement called magnetotaxis, driven by structures called magnetosomes. These magnetosomes consist of chains of magnetic particles made of either magnetite (Fe₃O₄) or greigite (Fe₃S₄) and are organized in a linear conformation by a protein scaffold within invaginations of the cell membrane. The bacteria align along the north–south magnetic field lines, much like a compass needle. They are typically microaerophilic or anaerobic...
322