通过Cdc2在体外光和激活13S凝聚素
K Kimura1, M Hirano, R Kobayashi
1Cold Spring Harbor Laboratory, Post Office Box 100, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
概括
在Xenopus蛋提取物中的线粒染色体凝结依赖于13S凝结素. 通过Cdc2激酶的酸化激活了这个复合体,这表明它在触发染色体凝聚过程中起着关键作用.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 13S凝聚素是Xenopus蛋提取物中线粒染色体凝聚的关键蛋白质复合物.
- 众所周知,这种复合物与DNA相互作用,并在细胞周期中受到调节.
研究的目的:
- 研究13S凝聚素诱导染色体凝聚的机制.
- 为了确定调节因素和途径参与激活13S凝聚素在线粒分裂过程中.
主要方法:
- 从Xenopus蛋提取物中净化13S凝固素.
- 在体外试验测试以评估在存在ATP和拓聚酶I的情况下的DNA超卷活动.
- 分解特异性酸化实验和免疫减弱研究.
- 片映射用于识别XCAP-D2子单元上的酸化位点.
主要成果:
- 纯化13S凝固素被证明可以在体外引入DNA中的正超线圈.
- 研究人员发现,13S凝聚素的超卷化活性通过线粒分裂特异性酸化来调节.
- 鉴定出Cdc2激酶可能是负责酸化和激活13S凝聚酶的酶.
- 多个Cdc2酸化部位被定位到XCAP-D2亚单元的炭基终端域.
结论:
- 通过Cdc2激酶对13S凝聚素的酸化是一个关键的调节事件.
- 建议这种酸化事件在体外引发线性染色体凝聚的启动.
- 这些发现阐明了细胞分裂期间染色体分离过程中的关键步骤.
相关概念视频
Positive Regulator Molecules
To consistently produce healthy cells, the cell cycle—the process that generates daughter cells—must be precisely regulated.
Positive Regulator Molecules
Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.
M-Cdk Drives Transition Into Mitosis
Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
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...
Anaphase Promoting Complex
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...


