コヘシンリングは,姉妹DNA分子を連結する
Christian H Haering1, Ana-Maria Farcas, Prakash Arumugam
1University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK.
Nature
|July 4, 2008
まとめ
細胞分裂に不可欠なタンパク質複合体であるコヘシンが,姉妹DNA分子を捕まえるリングを形成します. この研究は,化学的にコヘシン環を閉じ,ミトーシス中にDNA鎖を一緒に保持する役割を確認しました.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- 遺伝学 遺伝学とは
背景:
- 姉妹染色体凝結は,ミトーシス中の正確な染色体分離に不可欠です.
- Scc1,Smc1,Smc3のサブユニットからなるコヘシン複合体は,三部分環構造を形成する.
- リング・エントラップメント・モデルでは,コヘシンが姉妹DNA分子を包囲してコヘションを維持することを提案しています.
研究 の 目的:
- コヘシン関数のリングエントラップメントモデルを実験的に検証する.
- コヘシンが姉妹染色体の結束を媒介する構造的メカニズムを調査する.
主な方法:
- サイト固有のクロスリンクは,共振的に閉じられたコヘシンリングを作成するために使用されました.
- Scc1,Smc1,Smc3のサブユニット間のインターフェイスに化学的接続が導入されました.
- 改造されたコヘシンリングの安定性とDNA結合特性を評価した.
主要な成果:
- 結合的に閉ざされたコヘシンリングが成功裏に生成されました.
- これらの改変されたコヘシン構造は,二次元的なDNA-コヘシン複合体を形成した.
- DNA-コヘシン複合体はタンパク質デナチュレーションに対する耐性を示し,エントラップメントモデルを支持した.
結論:
- コヘシンリングは,個々の姉妹のミニクロモソームDNA分子を物理的に閉じ込めます.
- この研究は,姉妹染色体凝結のリングエントラップメントモデルに直接的な証拠を提供します.
- このメカニズムは,細胞分裂中にゲノムの安定性を維持するために不可欠です.
関連する概念動画
Cohesins
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...
Cohesins
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...
Condensins
Condensins are large protein complexes that use ATP to fuel the assembly of chromosomes during mitosis. They transform the tangled, shapeless mass of post-interphase DNA into individualized chromosomes by compacting, organizing, and segregating chromosomal DNA.
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
Condensins
Condensins are large protein complexes that use ATP to fuel the assembly of chromosomes during mitosis. They transform the tangled, shapeless mass of post-interphase DNA into individualized chromosomes by compacting, organizing, and segregating chromosomal DNA.
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
Separation 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...
Separation 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...

