Gadd45a通过修复介导的DNA脱甲基化促进表观遗传基因激活
Guillermo Barreto1, Andrea Schäfer, Joachim Marhold
1Division of Molecular Embryology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
Nature
|February 3, 2007
概括
增长停止和DNA损伤诱导蛋白45α (Gadd45a) 通过与DNA修复酶相互作用,驱动活性DNA脱甲基化. 这一过程消除了甲基化标记,缓解了表观遗传基因沉默并恢复了基因表达.
科学领域:
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 分子生物学分子生物学
- 基因组学就是基因组学.
背景情况:
- DNA甲基化对于基因沉默和基因组稳定至关重要.
- 活跃DNA脱甲基化的机制仍然不太清楚.
- 甲基转移酶的特征很好,但去甲基化途径不太清楚.
研究的目的:
- 研究Gadd45a在活性DNA脱甲基化中的作用.
- 阐明Gadd45a影响DNA甲基化的分子机制.
- 为了确定在去甲基化过程中与Gadd45a相互作用的蛋白质.
主要方法:
- 记者基因测试用于评估甲基化-沉默.
- Gadd45a过度表达和敲击下来的实验.
- 用于研究Oct4脱甲基化的Xenopus laevis卵细胞模型.
- 共同免疫沉以确定蛋白质相互作用.
主要成果:
- Gadd45a过度表达激活了甲基化沉默基因,并促进了全球脱甲基化.
- Gadd45a的淘汰导致了基因沉默和DNA高甲基化.
- Gadd45a被招募到去甲基化部位,并与XPG相互作用.
结论:
- Gadd45a 在活性DNA脱甲基化中起着关键作用.
- Gadd45a通过促进DNA修复而起作用,从而消除甲基化痕迹.
- 这种机制缓解了表观遗传基因沉默,并恢复了基因表达.
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...
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:
Gene Conversion
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
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...


