Hsu, J. W.J. W.HsuChen, Kuan-JungKuan-JungChenFang-Jen Scott Lee2019-08-282019-08-282015-07-222041-1723https://api.elsevier.com/content/abstract/scopus_id/84937870167https://scholars.lib.ntu.edu.tw/handle/123456789/416728Active GTP-bound Arf GTPases promote eukaryotic cell membrane trafficking and cytoskeletal remodelling. Arf activation is accelerated by guanine nucleotide-exchange factors (GEFs) using the critical catalytic glutamate in all known Sec7 domain sequences. Yeast Arf3p, a homologue of mammalian Arf6, is required for yeast invasive responses to glucose depletion. Here we identify Snf1p as a GEF that activates Arf3p when energy is limited. SNF1 is the yeast homologue of AMP-activated protein kinase (AMPK), which is a key regulator of cellular energy homeostasis. As activation of Arf3p does not depend on the Snf1p kinase domain, assay of regulatory domain fragments yield evidence that the C-terminal hydrophobic α-helix core of Snf1p is a non-canonical GEF for Arf3p activation. Thus, our study reveals a novel mechanism for regulating cellular responses to energy deprivation, in particular invasive cell growth, through direct Arf activation by Snf1/AMPK.en[SDGs]SDG7journal article10.1038/ncomms8840261980972-s2.0-84937870167WOS:000358861400001https://api.elsevier.com/content/abstract/scopus_id/84937870167