53BP1是DNA损伤诱导的H2A Lys 15泛素标记的读者
Amélie Fradet-Turcotte1, Marella D Canny, Cristina Escribano-Díaz
1Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada.
Nature
|June 14, 2013
概括
澄清了53BP1 (TP53BP1) 蛋白质对DNA双链断裂 (DSB) 位点的招募. 它可以识别特定的组合基因素标记,这是DNA修复过程中必不可少的.
科学领域:
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 修复DNA修复DNA的修复
背景情况:
- 53BP1 (TP53BP1) 对于DNA双链断裂 (DSB) 修复和免疫球蛋白类别切换至关重要.
- 53BP1对DSB位点的局部化取决于RNF168的泛素联酶,但泛素招募的机制尚不清楚.
- 53BP1的Tudor域识别了组分离子H4 Lysine 20 (H4K20) 甲基化,但它是如何被招募到破坏站点的仍然是未知的.
研究的目的:
- 阐明脊椎动物53BP1招募到染色质侧边DSB位点的机制.
- 为了确定在53BP1局部化中涉及的特定的基因素修饰和蛋白质域.
主要方法:
- 对53BP1与单核细胞体结合的分析.
- 53BP1域的特征,包括Tudor域和无处不在依赖招募 (UDR) 模式.
- 调查与修饰的质素H4K20me2和H2AK15ub.的相互作用.
主要成果:
- 53BP1识别了含有二甲基化H4K20 (H4K20me2) 的单核细胞.
- 53BP1还可以识别在氨酸15 (H2AK15ub) 上存在的H2A,这是RNF168.8的产物.
- 53BP1以二聚体的形式结合核体,利用其Tudor域用于H4K20me2和H2AK15ub的UDR动机.
结论:
- 53BP1作为一个双价素基因组修饰阅读器.
- 它破译了由DSB信号产生的一种特定的组素"代码",涉及H4K20me2和H2AK15ub.
- 这种机制解释了53BP1是如何被招募到DSB网站以进行高效的DNA修复.
相关概念视频
Nucleotide Excision Repair
Overview
Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
Spreading 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...
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...
Long-patch Base Excision Repair
Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:
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...


