Regulation of cardiac C-protein phosphorylation
Abstract
Molecular mechanisms of cardiac sympathetic and parasympathetic responses were addressed by studying subcellular changes in protein phosphorylation, cAMP-dependent protein kinase activity and protein phosphatase activity in frog hearts. B-adrenergic agonists increased and muscarinic cholinergic agonists decreased (/sup 32/P)phosphate incorporation into C-protein, a thick filament component. Regulation of protein phosphatase activity by Iso and methacholine (MCh) was assayed using extracts of drug treated frog hearts and (/sup 32/P)phospho-C-protein as substrate. Total phosphatase activity decreased 21% in extracts from hearts perfused with 0.1 ..mu..M Iso and 17% in hearts exposed to Iso plus 1 ..mu..M methacholine. This decrease reflected decreased phosphatase-2A activity. No changes in total phosphatase activity were measurable in broken cells treated with Iso or MCh. The results suggest adrenergic stimulation changes contractile activity in frog hearts by activating cAMP-dependent protein kinase associated with particulate cellular elements and inactivating soluble protein phosphatase-2A. This is the first demonstration of coordinated regulation of these enzymes by B-adrenergic agonists favoring phosphorylation of effector proteins. Coordinated regulation by methacholine in the presence of Iso was not observed.
- Authors:
- Publication Date:
- Research Org.:
- Emory Univ., Atlanta, GA (USA)
- OSTI Identifier:
- 6710064
- Resource Type:
- Thesis/Dissertation
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 59 BASIC BIOLOGICAL SCIENCES; PROTEINS; PHOSPHORYLATION; AUTONOMIC NERVOUS SYSTEM; FROGS; HEART; LABELLED COMPOUNDS; PHOSPHORUS 32; PHOSPHOTRANSFERASES; SYMPATHOMIMETICS; TRACER TECHNIQUES; AMPHIBIANS; ANIMALS; AQUATIC ORGANISMS; AUTONOMIC NERVOUS SYSTEM AGENTS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BODY; CARDIOVASCULAR SYSTEM; CHEMICAL REACTIONS; DAYS LIVING RADIOISOTOPES; DRUGS; ENZYMES; ISOTOPE APPLICATIONS; ISOTOPES; LIGHT NUCLEI; NERVOUS SYSTEM; NUCLEI; ODD-ODD NUCLEI; ORGANIC COMPOUNDS; ORGANS; PHOSPHORUS ISOTOPES; PHOSPHORUS-GROUP TRANSFERASES; RADIOISOTOPES; TRANSFERASES; VERTEBRATES; 550201* - Biochemistry- Tracer Techniques
Citation Formats
Titus, F L. Regulation of cardiac C-protein phosphorylation. United States: N. p., 1985.
Web.
Titus, F L. Regulation of cardiac C-protein phosphorylation. United States.
Titus, F L. 1985.
"Regulation of cardiac C-protein phosphorylation". United States.
@article{osti_6710064,
title = {Regulation of cardiac C-protein phosphorylation},
author = {Titus, F L},
abstractNote = {Molecular mechanisms of cardiac sympathetic and parasympathetic responses were addressed by studying subcellular changes in protein phosphorylation, cAMP-dependent protein kinase activity and protein phosphatase activity in frog hearts. B-adrenergic agonists increased and muscarinic cholinergic agonists decreased (/sup 32/P)phosphate incorporation into C-protein, a thick filament component. Regulation of protein phosphatase activity by Iso and methacholine (MCh) was assayed using extracts of drug treated frog hearts and (/sup 32/P)phospho-C-protein as substrate. Total phosphatase activity decreased 21% in extracts from hearts perfused with 0.1 ..mu..M Iso and 17% in hearts exposed to Iso plus 1 ..mu..M methacholine. This decrease reflected decreased phosphatase-2A activity. No changes in total phosphatase activity were measurable in broken cells treated with Iso or MCh. The results suggest adrenergic stimulation changes contractile activity in frog hearts by activating cAMP-dependent protein kinase associated with particulate cellular elements and inactivating soluble protein phosphatase-2A. This is the first demonstration of coordinated regulation of these enzymes by B-adrenergic agonists favoring phosphorylation of effector proteins. Coordinated regulation by methacholine in the presence of Iso was not observed.},
doi = {},
url = {https://www.osti.gov/biblio/6710064},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1985},
month = {Tue Jan 01 00:00:00 EST 1985}
}