Related Experiment Videos
Stimulation of the insulin-sensitive cAMP phosphodiesterase by an ATP-dependent soluble factor from insulin-treated
1Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0615.
Abstract:
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.