Phosphorylation of H,K-ATPase alpha-subunit in microsomes from rabbit gastric mucosa by cAMP-dependent protein kinase.
A 100-kDa protein that is a main component of the microsomal fraction from rabbit gastric mucosa is phosphorylated by cAMP-dependent protein kinase (PKA) in the presence of 0.2% Triton X-100. Microsomes from rabbit gastric mucosa possess activity of H,K-ATPase but not activity of Na,K-ATPase. Incubation of microsomes with 5 microM fluorescein 5'-isothiocyanate (FITC) results in both an inhibition of H,K-ATPase and labeling of a protein with an electrophoretic mobility corresponding to the mobility of the protein phosphorylated by PKA. The data suggest that the alpha-subunit of H,K-ATPase can be a potential target for PKA phosphorylation.
Murtazina
D A
DA
Department of Biochemistry, School of Biology, M.V. Lomonosov Moscow State University, Russia.
Petukhov
S P
SP
Storey
K B
KB
Rubtsov
A M
AM
Lopina
O D
OD
D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism*; D017506:H(+)-K(+)-Exchanging ATPase / Q000737:chemistry / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D011189:Potassium Chloride / Q000494:pharmacology; D054328:Proton Pump Inhibitors; D011817:Rabbits; D012965:Sodium Chloride / Q000494:pharmacology
D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D010761:Phosphorus Radioisotopes; D054328:Proton Pump Inhibitors; D012965:Sodium Chloride; D011189:Potassium Chloride; D017868:Cyclic AMP-Dependent Protein Kinases; D017506:H(+)-K(+)-Exchanging ATPase; D016650:Fluorescein-5-isothiocyanate