cdc25是一种特定的氨酸酸酶,直接激活p34cdc2
J Gautier1, M J Solomon, R N Booher
1Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
Cell
|October 4, 1991
概括
具体而言,CDC25蛋白酸酶对氨酸进行p34cdc2脱,从而激活环林-p34cdc2复合体,并在Xenopus卵细胞中启动M阶段.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 细胞循环是由蛋白激酶和酸酶调节的.
- CDC25是细胞循环的关键调节者,控制着环林-p34cdc2复合物的活性.
- 目前正在研究CDC25酸酶活性和基质特异性的精确机制.
研究的目的:
- 为了研究CDC25蛋白的酶活性和基质特异性.
- 要确定CDC25是否直接去p34cdc2并调节M阶段进入.
- 描述CDC25在控制p34cdc2.2.的酸化状态中的作用.
主要方法:
- 在细菌和酵母系统中Drosophila CDC25的表达.
- 在实验室中使用细菌表达的p34cdc2.2.的酸酶测定.
- 在Xenopus卵细胞和蛋提取物中分析M相诱导.
- 在CDC25的假定催化部位的局部定向突变发生.
主要成果:
- 多菌CDC25激活不活跃的环林-p34cdc2并诱导Xenopus卵细胞的M相.
- CDC25表现出与蛋白质氨酸酸酶的序列同质性.
- 细菌表达的CDC25在Tyr-15上的p34cdc2在体外特别脱.
- 催化部位的突变消除了体外和体内CDC25活动.
- CDC25对p34cdc2具有很高的特异性,对其他氨酸酸化蛋白质的脱酸化最小.
结论:
- CDC25是一种特定的蛋白质氨酸酸酶,在Tyr-15上直接去酸化p34cdc2.
- 这种脱化事件对于环林-p34cdc2复合物的激活和M相的启动至关重要.
- CDC25在通过p34cdc2.2.的特定脱化来调节MPF (促成成熟因子) 激活方面发挥着至关重要的作用.
相关概念视频
01:45Positive Regulator Molecules
To consistently produce healthy cells, the cell cycle—the process that generates daughter cells—must be precisely regulated.
02:39Positive 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.
02:34Inhibition of Cdk Activity
The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
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...
02:34Inhibition of CDK Activity
The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...