Aurelio A Teleman

Abstract Cells and organisms adjust their growth based on the availability of cholesterol, which is essential for cellular functions. However, the mechanisms by which cells sense cholesterol levels and translate these into growth signals are not fully understood. We report that cholesterol rapidly activates the master growth-regulatory TOR pathway in Drosophila tissues. We identify the nuclear receptor HR3, an ortholog of mammalian RORα, as an essential factor in cholesterol-induced TOR activation.

Abstract Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a regulator of cellular catabolism that is activated by AMP. As AMP accumulates in cells with low ATP, AMPK is considered a stress-activated kinase. While studying organ growth during Drosophila development, we find that AMPK can also be activated by a signalling metabolite not related to stress.

eLife Assessment In this valuable study, Roiuk et al combined ribosome profiling and reporter assays to provide compelling evidence that eIF2A does not have a major impact on mRNA translation in HeLa cells. These findings are consistent with several recent publications that disaffirm the previously proposed role of eIF2A in directing protein synthesis under stress.