Impaired ubiquitin-proteasome-mediated PGC-1alpha protein turnover and induced mitochondrial biogenesis secondary to complex-I deficiency

Item does not contain fulltext Most eukaryotic cells depend on mitochondrial OXidative PHOSphorylation (OXPHOS) in their ATP supply. The cellular consequences of OXPHOS defects and the pathophysiological mechanisms in related disorders are incompletely understood. Using a quantitative proteomics approach we provide evidence that a genetic defect of complex-I of the OXPHOS system may associate with transcriptional derangements of mitochondrial biogenesis through stabilization of the master transcriptional regulator PPARgamma co-activator 1alpha (PGC-1alpha) protein. Chronic oxidative stress suppresses the gene expression of PGC-1alpha but concomitant inhibition of the ubiquitin-proteasome system (UPS) can stabilize this co-activator protein, thereby inducing its downstream metabolic gene expression programs. Thus, mitochondrial biogenesis, which lays at the heart of the homeostatic control of energy metabolism, can be deregulated by secondary impairments of the protein turnover machinery. 01 mei 2012