テロメアの長さは,細胞サイクルを通じてTERRAとRループの調節を決定する.
Contact us if these videos are not relevant.
Contact us if these videos are not relevant.
PubMedで要約を見る
まとめ
この要約は機械生成です。短いテロメアは,RNAの劣化によるTERRARNA-DNAハイブリッド (R-ループ) の蓄積によってホモロジー誘導修復 (HDR) を誘発する. このプロセスは 細胞の老化を防ぐために不可欠です
科学分野
- 分子生物学
- 遺伝学
- 細胞生物学
背景
- 細胞の老化を防ぐには テロメアの長さを維持することが重要です
- ホモロジー・ディレクテッド・リペア (HDR) は,テロメラーゼが欠けていても,極めて短いテロメアを修復し,早期老化を防止します.
- HDRのための最短のテロメアの特定のターゲティングは不明である.
研究 の 目的
- 最短のテロメアがホモロジー指向修復 (HDR) の標的となるメカニズムを調査する.
- この過程における非コーディングRNA TERRAとRNA-DNAハイブリッド (Rループ) の役割を明らかにする.
- テロメアの複製と老化に及ぼす影響を理解する.
主な方法
- 異なる長さのテロメアでのTERRA蓄積の分析
- Rat1とRNase H2核酸を含むRNA分解経路の調査
- DNAダメージレスポンス (DDR) の活性化とRad51再結合酵素の募集の評価
主要な成果
- TERRAはHDR促進RNA-DNAハイブリッド (Rループ) として,特に非常に短いテロメアに蓄積されます.
- Rat1とRNase H2核酸によるRNA分解の局所的な欠陥は,短縮されたテロメアでTERRAとRループの増加を引き起こします.
- 短縮されたテロメアでのテロメア複製によるTERRA分解の調整の変化は,Rループの持続につながります.
結論
- テロメアの長さに依存するTERRAとRループの調節は,HDRターゲティングに極めて重要です.
- 短いテロメアでの持続的なRループは,DNA損傷応答 (DDR) を活性化し,Rad51の徴募を促進します.
- このメカニズムは 複製性老化の速度を決定します
関連する概念動画
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded...
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Overview
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the...
Replicative cell senescence is a property of cells that allows them to divide a finite number of times throughout the organism's lifespan while preventing excessive proliferation. Replicative senescence is associated with the gradual loss of the telomere — short, repetitive DNA sequences found at the end of the chromosomes. Telomeres are bound by a group of proteins to form a protective cap on the ends of chromosomes. Embryonic stem cells express telomerase — an enzyme that adds...
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
Three of the best-understood negative regulators are p53, p21, and retinoblastoma protein (Rb). The regulatory roles of each of these proteins were discovered after faulty copies were found in cells with uncontrolled replication (i.e.,...