Study on a novel pathway activating TORC1 published in eLife

The TOR kinase complex 1 (TORC1), conserved in all eukaryotic cells, plays a central role in control of cellular growth and autophagy according to nutrient availability, and its dysfunction is associated with several diseases. The activity of TORC1 is typically stimulated when amino acids are provided to amino-acid-starved cells. However, the signal eliciting this TORC1 reactivation in yeast has remained largely unknown. We now report in eLife that it is the influx of H+ coupled to amino acid uptake (via amino-acid/H+ symporters) that triggers this TORC1 activation, and that the plasma membrane H+-ATPase establishing the H+ gradient is a central actor of this mechanism. We propose the model that this H+-ATPase “senses” H+-coupled nutrient uptake and transmits this signal to TORC1. This study opens new perspectives for the study of nutrient sensing and growth control in other species.
This work has been mainly accomplished by Elie SALIBA, who recently defended his PhD thesis. It also involved a collaboration with Dr. Isabelle Georis (IRMW institute).  

Article : The yeast H+-ATPase Pma1 promotes Rag/Gtr-dependent TORC1 activation in response to H+-coupled nutrient uptake. Elie Saliba, Minoas Evangelinos, Christos Gournas, Florent Corrillon, Isabelle Georis &Bruno Andre. Elife (in press).