细胞染色体c和dATP依赖的Apaf-1/caspase-9复合体的形成启动了阿波性蛋白酶级联
P Li1, D Nijhawan, I Budihardjo
1Howard Hughes Medical Institute, and Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, 75235, USA.
Cell
|December 9, 1997
概括
这项研究确定了caspase-9作为亡级联中的关键蛋白质. 它激活了caspase-3,启动了由细胞染色体c和dATP触发的编程细胞死亡.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 卡斯巴酶-3激活是编程细胞死亡 (细胞亡) 的关键步骤.
- 众所周知,几个蛋白质因素参与了这个过程.
- 精确的上游激活剂的caspase-3还没有完全阐明.
研究的目的:
- 识别和描述参与卡斯巴-3激活的蛋白质因子.
- 阐明Apaf-3在caspase-3激活途径中的作用.
- 为了确定apoptotic蛋白酶级联的上游组件.
主要方法:
- 蛋白质净化以分离Apaf-3. 这种蛋白质的纯化.
- 在体外测试以研究蛋白质-蛋白质相互作用和酶激活.
- 在S-100提取物和体内进行的枯竭和突变研究.
- 对酶激活和细胞亡反应的分析.
主要成果:
- 鉴定出APAF-3为卡斯帕斯-9.
- 卡斯巴-9和阿帕夫-1通过它们的CED-3同源域结合,在细胞染色体c和dATP的存在下导致卡斯巴-9的激活.
- 激活的卡斯帕-9分裂并激活卡斯帕-3.
- 卡斯帕-9的枯竭或突变显著降低了卡斯帕-3的激活和体内亡反应.
结论:
- 卡斯巴-9是细胞染色体c/dATP触发的断蛋白质酶级联中最常被发现的上游蛋白质因子.
- 卡斯帕-9直接激活卡斯帕-3,在启动亡中起着至关重要的作用.
- 这一发现澄清了亡的内在途径中的关键调节步骤.
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