The main objective of this research is to investigate the biochemical interrelationship and mechanism of regulation of the multiple forms and factors of the cyclic nucleotide phosphodiesterase enzyme system. The direction of these studies is to test the hypothesis that a recently purified high affinity enzyme form is the basic catalytic subunit of mammalian cyclic nucleotide phosphodiesterase and that lower affinity forms are aggregates of this enzyme with itself and calcium dependent regulation (calmodulin), inhibitory binding protein, or other protein effectors. Biochemical, immunological, and pharmacological techniques will be employed for this purpose. Purified components of selected portions of the phosphodiesterase systems from kidney, brain, skeletal muscle, uterus, and acute myelogenous leukemic cells will be studied for their similarities and differences including kinetics, susceptibility to activation/inhibition, immunological crossreactivity and identity, peptide maps, drug binding, and substrate affinity labeling. Also, previously defined conditions for an integrated and systematic comparative study with linear sucrose gradient fractionation, behavior on ion-exchange celluloses, gel filtration, and isoelectric focusing will be used. Studies will be continued with cultured, synchronized Hela cells to define the role of cyclic nucleotide phosphodiesterases in the cell cycle and their susceptibility to cellular regulation. In addition, studies will be continued on the resposes of cyclic nucleotide phosphodiesterases of normal and leukemic leukocytes to serum, methylxanthines, and plant mitogens. These studies are designed to test our hypothesis that activation/inhibition occurs by protein synthetic-dependent and-independent mechanisms through the production of factors that modulate the activities of high and low affinity forms of cyclic nucleotide phosphodiesterases. Knowledge gained from these studies will be used to initiate additional studies on the regulation of high affinity, particulate cyclic nucleotide phosphodiesterase by insulin in normal and diabetic tissues and during the growth of cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM033538-04
Application #
3283413
Study Section
Biochemistry Study Section (BIO)
Project Start
1983-09-01
Project End
1989-03-31
Budget Start
1987-07-01
Budget End
1989-03-31
Support Year
4
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of South Alabama
Department
Type
Schools of Medicine
DUNS #
City
Mobile
State
AL
Country
United States
Zip Code
36688
Thompson, W J; Lavis, V R; Whalin, M E et al. (1992) Regulatory mechanisms of particulate cyclic nucleotide phosphodiesterases. Adv Second Messenger Phosphoprotein Res 25:165-84
Thompson, W J; Tan, B H; Strada, S J (1991) Activation of rabbit liver high affinity cAMP (type IV) phosphodiesterase by a vanadyl-glutathione complex. Characterization of the role of the sulfhydryl. J Biol Chem 266:17011-9
Whalin, M E; Scammell, J G; Strada, S J et al. (1991) Phosphodiesterase II, the cGMP-activatable cyclic nucleotide phosphodiesterase, regulates cyclic AMP metabolism in PC12 cells. Mol Pharmacol 39:711-7
Kithas, P A; Artman, M; Thompson, W J et al. (1989) Subcellular distribution of high-affinity type IV cyclic AMP phosphodiesterase activities in rabbit ventricular myocardium: relations to post-natal maturation. J Mol Cell Cardiol 21:507-17
Black, E W; Cornwell, T L; Lincoln, T M et al. (1989) Fura 2 analysis of cytosolic calcium regulation in elutriated rat gastric parietal cells. J Cell Physiol 139:632-40
Artman, M; Robertson, D W; Mahony, L et al. (1989) Analysis of the binding sites for the cardiotonic phosphodiesterase inhibitor [3H]LY186126 in ventricular myocardium. Mol Pharmacol 36:302-11
Black, E W; Strada, S J; Garrett Jr, R L et al. (1989) Inhibition of gastric acid secretion in vivo and in vitro by a new calmodulin antagonist, CGS 9343B. J Pharmacol Exp Ther 248:208-14
Strada, S J; Kithas, P A; Whalin, M E et al. (1989) Molecular properties of cyclic nucleotide phosphodiesterase isozymes. Adv Exp Med Biol 255:409-23
Artman, M; Kithas, P A; Wike, J S et al. (1989) Inotropic responses to cyclic nucleotide phosphodiesterase inhibitors in immature and adult rabbit myocardium. J Cardiovasc Pharmacol 13:146-54
Artman, M; Kithas, P A; Wike, J S et al. (1988) Inotropic responses change during postnatal maturation in rabbit. Am J Physiol 255:H335-42

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