共 56 条
Glycolytic enzymes associate dynamically with mitochondria in response to respiratory demand and support substrate channeling
被引:214
作者:
Graham, James W. A.
[1
]
Williams, Thomas C. R.
[1
]
Morgan, Megan
[1
]
Fernie, Alisdair R.
[2
]
Ratcliffe, R. George
[1
]
Sweetlove, Lee J.
[1
]
机构:
[1] Univ Oxford, Dept Plant Sci, Oxford OX1 3RB, England
[2] Max Planck Inst Mol Plant Physiol, D-14476 Potsdam, Germany
来源:
关键词:
D O I:
10.1105/tpc.107.053371
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
In Arabidopsis thaliana, enzymes of glycolysis are present on the surface of mitochondria and free in the cytosol. The functional significance of this dual localization has now been established by demonstrating that the extent of mitochondrial association is dependent on respiration rate in both Arabidopsis cells and potato (Solanum tuberosum) tubers. Thus, inhibition of respiration with KCN led to a proportional decrease in the degree of association, whereas stimulation of respiration by uncoupling, tissue ageing, or overexpression of invertase led to increased mitochondrial association. In all treatments, the total activity of the glycolytic enzymes in the cell was unaltered, indicating that the existing pools of each enzyme repartitioned between the cytosol and the mitochondria. Isotope dilution experiments on isolated mitochondria, using C-13 nuclear magnetic resonance spectroscopy to monitor the impact of unlabeled glycolytic intermediates on the production of downstream intermediates derived from C-13-labeled precursors, provided direct evidence for the occurrence of variable levels of substrate channeling. Pull-down experiments suggest that interaction with the outer mitochondrial membrane protein, VDAC, anchors glycolytic enzymes to the mitochondrial surface. It appears that glycolytic enzymes associate dynamically with mitochondria to support respiration and that substrate channeling restricts the use of intermediates by competing metabolic pathways.
引用
收藏
页码:3723 / 3738
页数:16
相关论文