Rapamycin Resistance: mTORC1 Substrates Hold Some of the Answers

Summary The mechanism of action of the mTOR inhibitor rapamycin is poorly understood and why certain mTORC1 phosphorylation sites are rapamycin insensitive remains elusive. Site-specific analysis of mTORC1 substrates now suggests that the sequence composition of a phosphorylation site determines whether it is sensitive to rapamycin and starvation.