细胞色素c和dATP依赖的Apaf-1/半胱天冬酶-9复合物的形成启动凋亡蛋白酶级联反应。

Cytochrome c and dATP-dependent formation of Apaf-1/caspase-9 complex initiates an apoptotic protease cascade.

作者信息

Li P, Nijhawan D, Budihardjo I, Srinivasula S M, Ahmad M, Alnemri E S, Wang X

机构信息

Howard Hughes Medical Institute, and Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, 75235, USA.

出版信息

Cell. 1997 Nov 14;91(4):479-89. doi: 10.1016/s0092-8674(00)80434-1.

DOI:10.1016/s0092-8674(00)80434-1

PMID:9390557

Abstract

We report here the purification of the third protein factor, Apaf-3, that participates in caspase-3 activation in vitro. Apaf-3 was identified as a member of the caspase family, caspase-9. Caspase-9 and Apaf-1 bind to each other via their respective NH2-terminal CED-3 homologous domains in the presence of cytochrome c and dATP, an event that leads to caspase-9 activation. Activated caspase-9 in turn cleaves and activates caspase-3. Depletion of caspase-9 from S-100 extracts diminished caspase-3 activation. Mutation of the active site of caspase-9 attenuated the activation of caspase-3 and cellular apoptotic response in vivo, indicating that caspase-9 is the most upstream member of the apoptotic protease cascade that is triggered by cytochrome c and dATP.

摘要

我们在此报告第三种蛋白因子Apaf-3的纯化，该因子参与体外半胱天冬酶-3的激活。Apaf-3被鉴定为半胱天冬酶家族的成员，即半胱天冬酶-9。在细胞色素c和dATP存在的情况下，半胱天冬酶-9和Apaf-1通过它们各自的氨基末端CED-3同源结构域相互结合，这一事件导致半胱天冬酶-9激活。激活的半胱天冬酶-9继而切割并激活半胱天冬酶-3。从S-100提取物中去除半胱天冬酶-9会减少半胱天冬酶-3的激活。半胱天冬酶-9活性位点的突变减弱了体内半胱天冬酶-3的激活和细胞凋亡反应，表明半胱天冬酶-9是由细胞色素c和dATP触发的凋亡蛋白酶级联反应中最上游的成员。