Abstract |
Polyphosphate ( polyP) consists of tens to hundreds of phosphates, linked by ATP-like high-energy bonds. Although polyP is present in mammalian mitochondria, its physiological roles there are obscure. Here, we examine the involvement of polyP in mitochondrial energy metabolism and ion transport. We constructed a vector to express a mitochondrially targeted polyphosphatase, along with a GFP fluorescent tag. Specific reduction of mitochondrial polyP, by polyphosphatase expression, significantly modulates mitochondrial bioenergetics, as indicated by the reduction of inner membrane potential and increased NADH levels. Furthermore, reduction of polyP levels increases mitochondrial capacity to accumulate calcium and reduces the likelihood of the calcium-induced mitochondrial permeability transition, a central event in many types of necrotic cell death. This confers protection against cell death, including that induced by beta-amyloid peptide, a pathogenic agent in Alzheimer's disease. These results demonstrate a crucial role played by polyP in mitochondrial function of mammalian cells.
|
Authors | Andrey Y Abramov, Cresson Fraley, Catherine T Diao, Robert Winkfein, Michael A Colicos, Michael R Duchen, Robert J French, Evgeny Pavlov |
Journal | Proceedings of the National Academy of Sciences of the United States of America
(Proc Natl Acad Sci U S A)
Vol. 104
Issue 46
Pg. 18091-6
(Nov 13 2007)
ISSN: 1091-6490 [Electronic] United States |
PMID | 17986607
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- NAD
- Green Fluorescent Proteins
- Adenosine Triphosphate
- Acid Anhydride Hydrolases
- endopolyphosphatase
- Calcium
|
Topics |
- Acid Anhydride Hydrolases
(metabolism)
- Adenosine Triphosphate
(metabolism)
- Calcium
(metabolism)
- Cell Death
- Cell Line
- Energy Metabolism
- Green Fluorescent Proteins
(metabolism)
- Humans
- Ion Transport
- Membrane Potentials
- Mitochondria
(enzymology, metabolism)
- NAD
(metabolism)
|