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Role of AMPK and PKA in the trafficking of V‐ATPase in kidney intercalated cells
Author(s) -
PastorSoler Nuria M.,
Gong Fan,
Alzamora Rodrigo,
Smolak Christy,
Thali Ramon,
Li Hui,
Neumann Dietbert,
Hallows Kenneth R.
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.1002.11
Subject(s) - ampk , phosphorylation , atpase , protein kinase a , microbiology and biotechnology , intercalated cell , chemistry , v atpase , biochemistry , biology , enzyme , secretion
Vacuolar ATPases (V‐ATPase) are expressed at the plasma membrane of type A intercalated cells (ICs) that acidify the lumen of kidney collecting duct. V‐ATPase function is important for acid excretion and defective V‐ATPase in ICs causes metabolic acidosis. V‐ATPase regulation by direct phosphorylation in mammalian epithelial cells is not well characterized. We have shown that in epididymal clear cells V‐ATPase accumulation at the apical membrane is regulated by cAMP/PKA and AMP‐activated kinase (AMPK). We hypothesized that V‐ATPase subcellular localization in ICs depends on phosphorylation of V 1 sector subunits and that V‐ATPase regulation is coupled to acid‐base status via PKA and to metabolic status via AMPK. Apical V‐ATPase accumulation in ICs requires cAMP/PKA, as evidenced immunofluorescence labeling of the V‐ATPase in kidney slices treated with various agonists and antagonists. In addition, AMPK activators prevented cAMP/PKA‐mediated V‐ATPase apical accumulation in ICs. Through mass spectrometry, mutagenesis and expression in cultured cells, we have identified several candidate PKA and AMPK phosphorylation sites in V 1 sector subunits that may have functional effects on V‐ATPase localization. We propose that subcellular localization and activity of the V‐ATPase in ICs depends on the direct phosphorylation of V 1 sector subunits by PKA and AMPK.