@article{abbede77995e4df7b5734d874068910f,
title = "An AMPKα2-specific phospho-switch controls lysosomal targeting for activation",
abstract = "AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin complex 1 (mTORC1) are metabolic kinases that co-ordinate nutrient supply with cell growth. AMPK negatively regulates mTORC1, and mTORC1 reciprocally phosphorylates S345/7 in both AMPK α-isoforms. We report that genetic or torin1-induced loss of α2-S345 phosphorylation relieves suppression of AMPK signaling; however, the regulatory effect does not translate to α1-S347 in HEK293T or MEF cells. Dephosphorylation of α2-S345, but not α1-S347, transiently targets AMPK to lysosomes, a cellular site for activation by LKB1. By mass spectrometry, we find that α2-S345 is basally phosphorylated at 2.5-fold higher stoichiometry than α1-S347 in HEK293T cells and, unlike α1, phosphorylation is partially retained after prolonged mTORC1 inhibition. Loss of α2-S345 phosphorylation in endogenous AMPK fails to sustain growth of MEFs under amino acid starvation conditions. These findings uncover an α2-specific mechanism by which AMPK can be activated at lysosomes in the absence of changes in cellular energy.",
keywords = "AMPK, energy homeostasis, kinase, lysosome, metabolic signaling, mTORC1, phosphorylation",
author = "Morrison, {Kaitlin R.} and Smiles, {William J.} and Ling, {Naomi X.Y.} and Ashfaqul Hoque and Gabrielle Shea and Ngoei, {Kevin R.W.} and Dingyi Yu and Lisa Murray-Segal and Scott, {John W.} and Sandra Galic and Kemp, {Bruce E.} and Janni Petersen and Oakhill, {Jonathan S.}",
note = "Funding Information: The generation of AMPK α2-S345A knockin mouse used in this study was supported by Phenomics Australia and the Australian Government through the National Collaborative Research Infrastructure Strategy (NCRIS) program. We thank Benoit Viollet (Institute Cochin) for AMPK α dKO iMEFs and Caroline Palmer (University of Melbourne) for Timm29 and PDI antibodies. S.G., B.E.K., J.W.S., and J.S.O. were supported by National Health and Medical Research Council (NHMRC) project grants ( GNT1145836 , GNT1138102 , and GNT1161262 ). K.R.M. and J.P. were supported by the NMHRC ( GNT1161262 ), Australian Research Council ( DP180101682 ), a Flinders Foundation seeding grant and Flinders University (Australia). This project was supported by St Vincent{\textquoteright}s Institute of Medical Research (Australia) and in part by the Victorian Government's Operational Infrastructure Support Program. Funding Information: The generation of AMPK ?2-S345A knockin mouse used in this study was supported by Phenomics Australia and the Australian Government through the National Collaborative Research Infrastructure Strategy (NCRIS) program. We thank Benoit Viollet (Institute Cochin) for AMPK ? dKO iMEFs and Caroline Palmer (University of Melbourne) for Timm29 and PDI antibodies. S.G. B.E.K. J.W.S. and J.S.O. were supported by National Health and Medical Research Council (NHMRC) project grants (GNT1145836, GNT1138102, and GNT1161262). K.R.M. and J.P. were supported by the NMHRC (GNT1161262), Australian Research Council (DP180101682), a Flinders Foundation seeding grant and Flinders University (Australia). This project was supported by St Vincent's Institute of Medical Research (Australia) and in part by the Victorian Government's Operational Infrastructure Support Program. K.R.M. W.J.S. N.X.Y.L. A.H. G.S. K.R.W.N. D.Y. and J.P. performed the experiments. L.M.-S. and S.G. supervised mouse and iMEF generation. J.W.S. and B.E.K. provided conceptual input. J.P. and J.S.O. conceived the study, and W.J.S. J.S.O. and J.P. wrote the initial draft. All authors contributed to the final manuscript. The authors declare no competing interests. One or more of the authors of this paper self-identifies as an underrepresented ethnic minority in science. While citing references scientifically relevant for this work, we also actively worked to promote gender balance in our reference list. Publisher Copyright: {\textcopyright} 2022 The Author(s)",
year = "2022",
month = feb,
day = "15",
doi = "10.1016/j.celrep.2022.110365",
language = "English",
volume = "38",
journal = "Cell Reports",
issn = "2211-1247",
publisher = "Elsevier",
number = "7",
}