イーストのテロメアの喪失:停止,回復,染色体の喪失
1Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
Cell
|November 19, 1993
まとめ
イーストのテロメアは,無傷の染色体と損傷したDNAを区別するために重要です. 欠落すると,細胞サイクル停止が起こりますが,修復系が活性化している場合でも,重要な染色体の不安定性と損失を引き起こします.
科学分野:
- 細胞生物学 細胞生物学
- 遺伝学 遺伝学とは
- 分子生物学は分子生物学である.
背景:
- テロメアは染色体の末端を分解と融合から保護する.
- RAD9経路のような細胞のチェックポイントは,DNAの損傷を検知し,異常な細胞分裂を防止します.
研究 の 目的:
- 染色体安定と細胞周期調節の維持におけるテロメアの役割を調査する.
- 酵母モデルにおけるテロメア喪失の影響を理解するために.
主な方法:
- 欠かせない染色体上の単一の,除去可能なテロメアを持つ酵母菌株の構築.
- テロメア除去後の細胞サイクル停止と染色体喪失の観察.
- テロメア喪失後の染色体安定性と分離の分析.
主要な成果:
- テロメアの除去は,RAD9媒介の細胞サイクル停止を誘発し,DNA損傷認識におけるテロメアの役割をシグナルしました.
- 多くの細胞は停止から回復したが,テロメアが欠けている染色体は,損失の劇的な増加を示した.
- テロメアが欠けている染色体は複製され,最終的に失われる前に最大10の分割のために分離されました.
結論:
- イーストのテロメアは,DNA損傷シグナル伝達と長期の染色体安定性の両方に不可欠です.
- チェックポイントと修復メカニズムは,テロメアを失った染色体の損失を防ぐのに不十分です.
- テロメアの整合性は,ゲノム不安定を防ぐために非常に重要です.
関連する概念動画
02:31Replication in Eukaryotes
Overview
02:41Telomeres and Telomerase
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 DNA.
02:15Replicative Cell Senescence
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 the telomeric...
01:12Loss of Tumor Suppressor Gene Functions
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
01:29Replication in Eukaryotes
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...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
02:41Telomeres and Telomerase
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 DNA.