通过对Cdc45p对染色质的S相环林CDK依赖的加载,形成一个预启动复合体
1Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Science (New York, N.Y.)
|May 9, 1998
概括
Cdc45p蛋白与染色质的结合对于DNA复制的启动至关重要. 这个过程需要循环素依赖激酶 (CDK) 活性,并且与细胞周期期间的预复制复合物有关.
科学领域:
- 分子生物学分子生物学
- 细胞循环规则 细胞循环规则
- 复制DNA复制DNA复制DNA复制
背景情况:
- Cdc45p是参与启动DNA复制的关键蛋白质.
- 它与染色质的关联发生在G1后期和整个S阶段的"开始"后.
- 了解Cdc45p的染色体结合对于理解DNA复制控制至关重要.
研究的目的:
- 调查控制Cdc45p与染色素相关性的调控机制.
- 确定循环素依赖激酶 (CDK) 和其他蛋白质在Cdc45p染色体结合中的作用.
- 为了阐明Cdc45p和微染色体维护 (MCM) 蛋白质从染色质中的解离动态.
主要方法:
- 在酵母中进行细胞循环分析.
- 染色体免疫沉测定. 染色体免疫沉测定.
- 蛋白质与蛋白质相互作用的分析.
主要成果:
- Cdc45p染色体关联取决于Clb-Cdc28激酶活性和功能性的Cdc6p和Mcm2p.
- 在S相CDK激活后,Cdc45p与染色质结合,表明其在预复制复合体组合中的作用.
- 在S阶段,Cdc45p与MCM蛋白进行物理相互作用,但与MCM相比,与染色质的分离速度较慢.
结论:
- Cdc45p染色体结合是启动DNA复制的关键,CDK依赖的步骤.
- 不同的解离速率表明,Cdc45p和MCM蛋白质从染色质中释放的机制是不同的.
- 这项研究提供了对DNA复制启动和进展的时间调节的见解.
相关概念视频
02:38S-Cdk Initiates DNA Replication
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
02:15M-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...
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...
00:50Anaphase 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...
02:38S-Cdk Initiates DNA Replication
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
00:50Anaphase 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...