|
|
|
|
A more recent version of this article appeared on September 1, 2007
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on December 15, 2006
Revised on June 11, 2007
Accepted on June 14, 2007
*Cell Biology Laboratory, Department of Biochemistry, BioSciences Institute, National University of Ireland, Cork, Ireland;
Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, and Consiglio Nazionale delle Ricerche Institute of Biomembranes and Bioenergetics, Bari, Italy;
Institute of Pathology, University Hospital Mannheim, University of Heidelberg, Germany;
Medical Research Council, Dunn Human Nutrition Unit, Cambridge CB2 2XY, United Kingdom
Monitoring Editor: Carl-Henrik Heldin
The Insulin/IGF signaling pathway to mTOR is essential for the survival and growth of normal cells and also contributes to the genesis and progression of cancer. This signaling pathway is linked with regulation of mitochondrial function, but how is incompletely understood. Here we show that IGF-I and insulin induce rapid transcription of the mitochondrial pyrimidine nucleotide carrier PNC1, which shares significant identity with the essential yeast mitochondrial carrier Rim2p. PNC1 expression is dependent on PI3-kinase and mTOR activity and is higher in transformed fibroblasts, cancer cell lines, and primary prostate cancers than in normal tissues. Overexpression of PNC1 enhances cell size, whereas suppression of PNC1 expression causes reduced cell size, and retarded cell cycle progression and proliferation. Cells with suppressed PNC1 expression have reduced mitochondrial UTP levels, but mitochondrial mass and cellular ATP are not altered. Overall the data indicate that PNC1 is a target of the IGF-I/mTOR pathway that is essential for mitochondrial activity in regulating cell growth and proliferation.
This article has been cited by other articles:
![]() |
Y. Xu, M. Johansson, and A. Karlsson Human UMP-CMP Kinase 2, a Novel Nucleoside Monophosphate Kinase Localized in Mitochondria J. Biol. Chem., January 18, 2008; 283(3): 1563 - 1571. [Abstract] [Full Text] [PDF] |
||||