Coordinated regulation of protein synthesis and mitochondrial respiration by the molecular chaperone TRAP1 in cancer cells

Here we show that TRAP1 directly binds translation elongation factors, both inside and outside mitochondria, and slows down translation. TRAP1 overexpression or silencing affects the synthesis of respiratory complex components. Inside mitochondria, TRAP1 binds the Complex III core component UQCRC2 and regulates Complex III activity. This decreases respiration rate upon basal condition but allows sustained oxidative phosphorylation when glucose is limiting, a condition in which TRAP1-UQCRC2 binding is lost. In humans, TRAP1 is co-expressed with the mitochondrial translational machinery, which synthesize respiratory complex proteins. Altogether, our results show an unprecedented level of complexity in the regulation of cancer cell metabolism, in which mitochondrial and cytosolic protein synthesis are co-regulated with energetic metabolism through the contribution of a common molecular chaperone Evaluation of differentially expressed transcripts in sh TRAP1 over sh GFP, and in hyper TRAP1 over hyper GFP expressing HeLa cells