Stimulation of the insulin-sensitive cAMP phosphodiesterase by an ATP-dependent soluble factor from insulin-treated rat adipocytes.
The insulin-sensitive cAMP phosphodiesterase (PDE) in the microsomal fraction (Fraction P-2) from basal (-insulin) rat adipocytes was stimulated upon incubation with 2 mM ATP plus the soluble fraction from insulin-treated adipocytes (Fraction S-2+). Fraction S-2+ was prepared in the presence of p-nitrophenylphosphate, sodium vanadate, and EGTA. The ATP-dependent stimulation of PDE was routinely 60-70%. The unknown factor in Fraction S-2 was water-soluble, heat-labile, excluded by Sephadex G-50, mostly retained by Sephadex G-100, and not inhibited with 1 microgram/ml heparin, 3 mM CaCl2, or 30 mM NaF. The soluble factor may be a mediator of insulin action on PDE, possibly a protein kinase.
Shibata
H
H
Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0615.
Kono
T
T
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D000818:Animals; D002478:Cells, Cultured; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008861:Microsomes / Q000201:enzymology; D051381:Rats; D011919:Rats, Inbred Strains; D014020:Tissue Extracts / Q000494:pharmacology*; D014638:Vanadates / Q000494:pharmacology
D007328:Insulin; D014020:Tissue Extracts; D014638:Vanadates; D000255:Adenosine Triphosphate; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D008274:Magnesium