Structural highlights
Function
APAF_HUMAN Oligomeric Apaf-1 mediates the cytochrome c-dependent autocatalytic activation of pro-caspase-9 (Apaf-3), leading to the activation of caspase-3 and apoptosis. This activation requires ATP. Isoform 6 is less effective in inducing apoptosis.[1] [2]
Publication Abstract from PubMed
Autocatalytic activation of an initiator caspase triggers the onset of apoptosis. In dying cells, caspase-9 activation is mediated by a multimeric adaptor complex known as the Apaf-1 apoptosome. The molecular mechanism by which caspase-9 is activated by the Apaf-1 apoptosome remains largely unknown. Here we demonstrate that the previously reported 1:1 interaction between Apaf-1 caspase recruitment domain (CARD) and caspase-9 CARD is insufficient for the activation of caspase-9. Rather, formation of a multimeric CARD:CARD assembly between Apaf-1 and caspase-9, which requires three types of distinct interfaces, underlies caspase-9 activation. Importantly, an additional surface area on the multimeric CARD assembly is essential for caspase-9 activation. Together, these findings reveal mechanistic insights into the activation of caspase-9 by the Apaf-1 apoptosome and support the induced conformation model for initiator caspase activation by adaptor complexes.
Molecular determinants of caspase-9 activation by the Apaf-1 apoptosome.,Hu Q, Wu D, Chen W, Yan Z, Yan C, He T, Liang Q, Shi Y Proc Natl Acad Sci U S A. 2014 Nov 18;111(46):16254-61. doi:, 10.1073/pnas.1418000111. Epub 2014 Oct 13. PMID:25313070[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Hu Y, Benedict MA, Ding L, Nunez G. Role of cytochrome c and dATP/ATP hydrolysis in Apaf-1-mediated caspase-9 activation and apoptosis. EMBO J. 1999 Jul 1;18(13):3586-95. PMID:10393175 doi:10.1093/emboj/18.13.3586
- ↑ Ogawa T, Shiga K, Hashimoto S, Kobayashi T, Horii A, Furukawa T. APAF-1-ALT, a novel alternative splicing form of APAF-1, potentially causes impeded ability of undergoing DNA damage-induced apoptosis in the LNCaP human prostate cancer cell line. Biochem Biophys Res Commun. 2003 Jun 27;306(2):537-43. PMID:12804598
- ↑ Hu Q, Wu D, Chen W, Yan Z, Yan C, He T, Liang Q, Shi Y. Molecular determinants of caspase-9 activation by the Apaf-1 apoptosome. Proc Natl Acad Sci U S A. 2014 Nov 18;111(46):16254-61. doi:, 10.1073/pnas.1418000111. Epub 2014 Oct 13. PMID:25313070 doi:http://dx.doi.org/10.1073/pnas.1418000111
