起源認識複合体は,Saccharomyces cerevisiaeの姉妹染色体結合において機能する
Kenji Shimada1, Susan M Gasser
1Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
Cell
|January 16, 2007
まとめ
起源認識複合体 (ORC) タンパク質Orc2は,細胞分裂中に姉妹染色体結合を維持するために不可欠です. Orc2の枯渇は結束を損なっており,DNA複製を超えた染色体分離におけるORCの新たな役割を強調しています.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- 高精度染色体分離は,主にコヘシン複合体によって媒介される時宜的な姉妹染色体結合に依存する.
- メタフェーズからアナフェーズへの移行時のコヘシンの解像度は,正確な細胞分裂に不可欠です.
研究 の 目的:
- 細胞サイクル進行と姉妹染色体凝結における起源認識複合体 (ORC) タンパク質Orc2の役割を調査する.
- Orc2がクロマチンとのコヘシン複合体の関連から独立してコヘションに影響を与えるかどうかを判断する.
主な方法:
- 前複製複合組立後の酵母菌株におけるOrc2の枯渇.
- 細胞サイクル進行,DNA損傷,およびスパインドルのチェックポイントの分析.
- 姉妹染色体凝結とコヘシン亜単位の局所化の評価.
- Orc2の再発現とターゲットローカライゼーション研究.
主要な成果:
- Orc2の枯渇は,DNA損傷とスパインドルチェックポイントの活性化により,ミトーシスを遅らせます.
- 姉妹染色体の凝結は,正常なCohesin関連にもかかわらず,Orc2が枯渇した細胞で損なわれていました.
- Orc2の再発現により,染色体の結合が回復した.
- 特定の位置にOrc2をターゲットにすることで,コヘシン変異体における早期の姉妹染色体分離が抑制された.
結論:
- 起源認識複合体 (ORC) は,姉妹染色体の結束の確立と維持に重要な役割を果たします.
- ORC媒介の凝結は,Cohesin媒介のペアリングへの経路添加物で作用する.
- Orc2は,姉妹染色体結合における役割を通じて,適切な染色体分離に不可欠です.
関連する概念動画
02:20Cohesins
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
02:57Attachment of Sister Chromatids
As cells progress into mitosis, the nuclear envelope breaks down, and the condensed chromosomes are exposed to the array of bipolar microtubules of the mitotic spindle. The kinetochore, a large, disc-shaped protein complex, is present at the centromere region of the sister chromatids and acts as a binding site for the microtubules. Usually, the plus-end of a single microtubule is embedded within the kinetochore. However, some kinetochores first establish lateral contact with the side-wall of a...
02:17Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
02:20Cohesins
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
02:57Attachment of Sister Chromatids
As cells progress into mitosis, the nuclear envelope breaks down, and the condensed chromosomes are exposed to the array of bipolar microtubules of the mitotic spindle. The kinetochore, a large, disc-shaped protein complex, is present at the centromere region of the sister chromatids and acts as a binding site for the microtubules. Usually, the plus-end of a single microtubule is embedded within the kinetochore. However, some kinetochores first establish lateral contact with the side-wall of a...
02:17Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...