在DNA修复过程中,Saccharomyces cerevisiae histone H2A 的作用
J A Downs1, N F Lowndes, S P Jackson
1The Wellcome Trust and Cancer Research Campaign, Institute of Cancer and Developmental Biology, and Department of Zoology, University of Cambridge, UK.
Nature
|January 5, 2001
概括
通过Mec1对基因素H2A的酸化对DNA双链断裂修复和染色质结构至关重要. 这种修改通过促进非同类末端连接修复通路来提高生存率.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 细胞生物学 细胞生物学
背景情况:
- 基因组蛋白将DNA压缩成核体,形成对核过程至关重要的染色体.
- 染色体结构调节对于DNA复制和转录至关重要.
- DNA损伤反应途径可能与染色质结构调节相互作用.
研究的目的:
- 来自Saccharomyces cerevisiae. histone H2A中的一个保存的图案的特征.
- 为了研究这种基因酸化在DNA双链断裂修复中的作用.
- 确定图案对染色质结构和细胞存活的影响.
主要方法:
- 在基因素H2A中保存图案的表征.
- 对酸-3-OH激酶相关激酶 (PIKKs) 的酸化部位的分析.
- 评估对DNA损伤剂的反应生存率.
- 研究DNA修复机制,特别是非同源端结合.
- 评估对高阶染色体结构的影响.
主要成果:
- 在基因素H2A中发现了一种具有PIKK酸化位点的保存基因.
- 这种基因由Mec1的酸化是由DNA损伤引起的.
- 这种动图对于DNA双链断裂后的生存至关重要.
- 它是有效的非同类末端连接修复所需的.
- 图案影响了更高阶的染色体结构.
结论:
- 通过Mec1酸化素H2A在DNA双链断裂修复中起着至关重要的作用.
- 这种修改会影响染色质结构,促进有效的DNA修复.
- 识别的动机是DNA损伤反应途径的关键组成部分.
相关概念视频
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:25Spreading of Chromatin Modifications
The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
Writers
The writer is an enzyme that can...
Writers
The writer is an enzyme that can...
02:04Fixing Double-strand Breaks
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
02:36DNA Damage can Stall the Cell Cycle
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...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:36DNA Damage Can Stall the Cell Cycle
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...