title: Aurora kinase A activates the vacuolar H+-ATPase (V-ATPase) in kidney carcinoma cells.
abstract: Extracellular proton-secreting transport systems that contribute to extracellular pH include the vacuolar H(+)-ATPase (V-ATPase). This pump, which mediates ATP-driven transport of H(+) across membranes, is involved in metastasis. We previously showed (Alzamora R, Thali RF, Gong F, Smolak C, Li H, Baty CJ, Bertrand CA, Auchli Y, Brunisholz RA, Neumann D, Hallows KR, Pastor-Soler NM. J Biol Chem 285: 24676-24685, 2010) that V-ATPase A subunit phosphorylation at Ser-175 is important for PKA-induced V-ATPase activity at the membrane of kidney intercalated cells. However, Ser-175 is also located within a larger phosphorylation consensus sequence for Aurora kinases, which are known to phosphorylate proteins that contribute to the pathogenesis of metastatic carcinomas. We thus hypothesized that Aurora kinase A (AURKA), overexpressed in aggressive carcinomas, regulates the V-ATPase in human kidney carcinoma cells (Caki-2) via Ser-175 phosphorylation. We found that AURKA is abnormally expressed in Caki-2 cells, where it binds the V-ATPase A subunit in an AURKA phosphorylation-dependent manner. Treatment with the AURKA activator anacardic acid increased V-ATPase expression and activity at the plasma membrane of Caki-2 cells. In addition, AURKA phosphorylates the V-ATPase A subunit at Ser-175 in vitro and in Caki-2 cells. Immunolabeling revealed that anacardic acid induced marked membrane accumulation of the V-ATPase A subunit in transfected Caki-2 cells. However, anacardic acid failed to induce membrane accumulation of a phosphorylation-deficient Ser-175-to-Ala (S175A) A subunit mutant. Finally, S175A-expressing cells had decreased migration in a wound-healing assay compared with cells expressing wild-type or a phospho-mimetic Ser-175-to-Asp (S175D) mutant A subunit. We conclude that AURKA activates the V-ATPase in kidney carcinoma cells via phosphorylation of Ser-175 in the V-ATPase A subunit. This regulation contributes to kidney carcinoma V-ATPase-mediated extracellular acidification and cell migration.
authors.affiliation: Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and.
authors.forename: Mohammad M
authors.initials: MM
authors.lastname: Al-Bataineh
authors.affiliation: Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Alzamora
authors.affiliation: Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ohmi
authors.affiliation: Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California.
authors.forename: Pei-Yin
authors.initials: PY
authors.lastname: Ho
authors.affiliation: Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Marciszyn
authors.affiliation: Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and.
authors.forename: Fan
authors.initials: F
authors.lastname: Gong
authors.affiliation: Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California hallows@usc.edu.
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Hallows
authors.affiliation: Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California.
authors.forename: Núria M
authors.initials: NM
authors.lastname: Pastor-Soler
mesh_terms: D048729:Anacardic Acids / Q000494:pharmacology; D064096:Aurora Kinase A / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D025262:Vacuolar Proton-Translocating ATPases / Q000378:metabolism*
chemical_list: D048729:Anacardic Acids; C088115:anacardic acid; D064096:Aurora Kinase A; D025262:Vacuolar Proton-Translocating ATPases
keywords: cancer; epithelial cell; pH regulation; plasma membrane; proton pump