AMPK phosphosite profiling by label-free mass spectrometry reveals a multitude of mTORC1-regulated substrates.

ABSTRACT: The nutrient-sensitive protein kinases AMPK and mTORC1 form a fundamental negative feedback loop that governs cell growth and proliferation. mTORC1 phosphorylates α2-S345 in the AMPK αβγ heterotrimer to suppress its activity and promote cell proliferation under nutrient stress conditions. Whether AMPK contains other functional mTORC1 substrates is unknown. Using mass spectrometry, we generated precise stoichiometry profiles of phosphorylation sites across all twelve AMPK complexes expressed in proliferating human cells and identified seven sites displaying sensitivity to pharmacological mTORC1 inhibition. These included the abundantly phosphorylated residues β1-S182 and β2-S184, which were confirmed as mTORC1 substrates on purified AMPK, and four residues in the unique γ2 N-terminal extens

SUBMITTER: Smiles WJ 

PROVIDER: S-EPMC11879883 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature