New insights into the bioenergetics of mitochondrial disorders using intracellular ATP reporters. Academic Article uri icon

Overview

abstract

  • Mutations in mitochondrial DNA (mtDNA) cause impairment of ATP synthesis. It was hypothesized that high-energy compounds, such as ATP, are compartmentalized within cells and that different cell functions are sustained by different pools of ATP, some deriving from mitochondrial oxidative phosphorylation (OXPHOS) and others from glycolysis. Therefore, an OXPHOS dysfunction may affect different cell compartments to different extents. To address this issue, we have used recombinant forms of the ATP reporter luciferase localized in different cell compartments- the cytosol, the subplasma membrane region, the mitochondrial matrix, and the nucleus- of cells containing either wild-type or mutant mtDNA. We found that with glycolytic substrates, both wild-type and mutant cells were able to maintain adequate ATP supplies in all compartments. Conversely, with the OXPHOS substrate pyruvate ATP levels collapsed in all cell compartments of mutant cells. In wild-type cells normal levels of ATP were maintained with pyruvate in the cytosol and in the subplasma membrane region, but, surprisingly, they were reduced in the mitochondria and, to a greater extent, in the nucleus. The severe decrease in nuclear ATP content under "OXPHOS-only" conditions implies that depletion of nuclear ATP plays an important, and hitherto unappreciated, role in patients with mitochondrial dysfunction.

publication date

  • June 27, 2003

Research

keywords

  • DNA, Mitochondrial
  • Energy Metabolism
  • Mitochondria
  • Mitochondrial Diseases
  • Mitochondrial Proton-Translocating ATPases

Identity

PubMed Central ID

  • PMC196555

Scopus Document Identifier

  • 0141521643

Digital Object Identifier (DOI)

  • 10.1091/mbc.e02-12-0796

PubMed ID

  • 12972552

Additional Document Info

volume

  • 14

issue

  • 9