Gadd45aは,修復媒介によるDNA脱メチル化によって表遺伝子遺伝子の活性化を促進する
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
まとめ
成長停止とDNA損傷誘導性タンパク質45α (Gadd45a) は,DNA修復酵素と相互作用することによって,活性DNA脱甲基化を誘導する. このプロセスはメチレーションマークを消し去り,エピジェネティック遺伝子サイレンシングを緩和し,遺伝子発現を回復します.
科学分野:
- エピジェネティクス エピジェネティクス
- 分子生物学は分子生物学である.
- ゲノミクスゲノミクスとは
背景:
- DNAメチル化は,遺伝子サイレンシングとゲノムの安定性にとって極めて重要です.
- 活性DNA脱メチル化のメカニズムは未だに十分に理解されていない.
- メチルトランスフェラーゼはよく特徴づけられていますが,脱メチル化経路はそれほど明確ではありません.
研究 の 目的:
- 活性DNA脱メチル化におけるGadd45aの役割を調査する.
- Gadd45aがDNAメチレーションに影響を与える分子メカニズムを解明する.
- 脱メチル化中にGadd45aと相互作用するタンパク質を特定するために.
主な方法:
- レポーター遺伝子解析は,メチル化-静止を評価する.
- Gadd45a 過剰表現とノックダウン実験.
- oct4脱メチル化を研究するためのXenopus laevis卵細胞モデル.
- タンパク質の相互作用を特定するための共免疫プレシピテーション.
主要な成果:
- Gadd45aの過剰発現はメチル化抑制遺伝子を活性化させ,全局的な脱メチル化を促進した.
- Gadd45aのノックダウンは,遺伝子サイレンスとDNAハイパーメチル化につながった.
- Gadd45aは脱メチル化部位に誘導され,XPGと相互作用した.
結論:
- Gadd45aは,活性DNA脱甲基化に重要な役割を果たしています.
- Gadd45aはDNA修復を促進し,メチル化痕跡を消去することで機能します.
- このメカニズムは,エピジェネティック遺伝子サイレンシングを緩和し,遺伝子発現を回復します.
関連する概念動画
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...


