Molecular and Cellular Biology, November 2001, p. 7268-7276, Vol. 21, No. 21
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.21.7268-7276.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Cancer Research Campaign Molecular Pharmacology Group, School of Biological Sciences, University of Manchester, Manchester M13 9PT, United Kingdom,1 and Institut de Recherches Servier, Suresnes 92150, Paris, France2
Received 16 July 2001/Accepted 13 August 2001
Bid is an abundant proapoptotic protein of the Bcl-2 family that is crucial for the induction of death receptor-mediated apoptosis in primary tissues such as liver. Bid action has been proposed to involve the relocation of its truncated form, tBid, to mitochondria to facilitate the release of apoptogenic cytochrome c. The mechanism of Bid relocation to mitochondria was unclear. We report here novel biochemical evidence indicating that Bid has lipid transfer activity between mitochondria and other intracellular membranes, thereby explaining its dynamic relocation to mitochondria. First, physiological concentrations of phospholipids such as phosphatidic acid and phosphatidylgycerol induced an accumulation of full-length Bid in mitochondria when incubated with light membranes enriched in endoplasmic reticulum. Secondly, native and recombinant Bid, as well as tBid, displayed lipid transfer activity under the same conditions and at the same nanomolar concentrations leading to mitochondrial relocation and release of cytochrome c. Thus, Bid is likely to be involved in the transport and recycling of mitochondrial phospholipids. We discuss how this new role of Bid may relate to its proapoptotic action.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|