title: AMPK and Endothelial Nitric Oxide Synthase Signaling Regulates K-Ras Plasma Membrane Interactions via Cyclic GMP-Dependent Protein Kinase 2.
abstract: K-Ras must localize to the plasma membrane and be arrayed in nanoclusters for biological activity. We show here that K-Ras is a substrate for cyclic GMP-dependent protein kinases (PKGs). In intact cells, activated PKG2 selectively colocalizes with K-Ras on the plasma membrane and phosphorylates K-Ras at Ser181 in the C-terminal polybasic domain. K-Ras phosphorylation by PKG2 is triggered by activation of AMP-activated protein kinase (AMPK) and requires endothelial nitric oxide synthase and soluble guanylyl cyclase. Phosphorylated K-Ras reorganizes into distinct nanoclusters that retune the signal output. Phosphorylation acutely enhances K-Ras plasma membrane affinity, but phosphorylated K-Ras is progressively lost from the plasma membrane via endocytic recycling. Concordantly, chronic pharmacological activation of AMPK → PKG2 signaling with mitochondrial inhibitors, nitric oxide, or sildenafil inhibits proliferation of K-Ras-positive non-small cell lung cancer cells. The study shows that K-Ras is a target of a metabolic stress-signaling pathway that can be leveraged to inhibit oncogenic K-Ras function.
authors.affiliation: Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Medical School, Houston, Texas, USA.
authors.forename: Kwang-Jin
authors.initials: KJ
authors.lastname: Cho
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla, California, USA.
authors.forename: Darren E
authors.initials: DE
authors.lastname: Casteel
authors.affiliation: Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Medical School, Houston, Texas, USA.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Prakash
authors.affiliation: Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Medical School, Houston, Texas, USA.
authors.forename: Lingxiao
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Diagnostic and Biomedical Sciences, University of Texas Health Science Center at Houston, School of Dentistry, Houston, Texas, USA.
authors.forename: Dharini
authors.initials: D
authors.lastname: van der Hoeven
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
authors.forename: Angela A
authors.initials: AA
authors.lastname: Salim
authors.affiliation: Department of Pharmacology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Choel
authors.initials: C
authors.lastname: Kim
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Capon
authors.affiliation: Microbial Screening Technologies Pty., Ltd., Smithfield, New South Wales, Australia.
authors.forename: Ernest
authors.initials: E
authors.lastname: Lacey
authors.affiliation: Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Medical School, Houston, Texas, USA.
authors.forename: Shane R
authors.initials: SR
authors.lastname: Cunha
authors.affiliation: Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Medical School, Houston, Texas, USA.
authors.forename: Alemayehu A
authors.initials: AA
authors.lastname: Gorfe
authors.affiliation: Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Medical School, Houston, Texas, USA john.f.hancock@uth.tmc.edu.
authors.forename: John F
authors.initials: JF
authors.lastname: Hancock
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects; D062967:Cyclic GMP-Dependent Protein Kinase Type II / Q000378:metabolism*; D004285:Dogs; D004705:Endocytosis; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism*; D061985:Madin Darby Canine Kidney Cells; D009569:Nitric Oxide / Q000494:pharmacology; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010766:Phosphorylation; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction; D000068677:Sildenafil Citrate / Q000494:pharmacology; D018631:ras Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D009569:Nitric Oxide; D012694:Serine; D000068677:Sildenafil Citrate; D052250:Nitric Oxide Synthase Type III; D062967:Cyclic GMP-Dependent Protein Kinase Type II; D055372:AMP-Activated Protein Kinases; D018631:ras Proteins