期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：32
页码：11880-11885
DOI：10.1073/pnas.0401703101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The mitochondrial ATP-sensitive K+ (mitoKATP) channel plays a central role in protection of cardiac and neuronal cells against ischemia and apoptosis, but its molecular structure is unknown. Succinate dehydrogenase (SDH) is inhibited by mitoKATP activators, fueling the contrary view that SDH, rather than mitoKATP, is the target of cardioprotective drugs. Here, we report that SDH forms part of mitoKATP functionally and structurally. Four mitochondrial proteins [mitochondrial ATP-binding cassette protein 1 (mABC1), phosphate carrier, adenine nucleotide translocator, and ATP synthase] associate with SDH. A purified IM fraction containing these proteins was reconstituted into proteoliposomes and lipid bilayers and shown to confer mitoKATP channel activity. This channel activity is sensitive not only to mitoKATP activators and blockers but also to SDH inhibitors. These results reconcile the controversy over the basis of ischemic preconditioning by demonstrating that SDH is a component of mitoKATP as part of a macromolecular supercomplex. The findings also provide a tangible clue as to the structural basis of mitoKATP channels.
