Physiological role of phosphorylation of the cyclic AMP response element binding protein in rat cardiac nuclei. Cell Tissue Res 1996 Sep;285(3):379-85
Date
09/01/1996Pubmed ID
8772151DOI
10.1007/s004410050653Scopus ID
2-s2.0-0029790453 (requires institutional sign-in at Scopus site) 17 CitationsAbstract
We determine whether the cyclic AMP signal transduction pathway affects phosphorylation of cyclic AMP response element binding protein and increases muscle gene expression in the heart. Elevation of cyclic AMP results in phosphorylation of the binding protein which is detected using an antibody specific for the phosphorylated, but not the unphosphorylated, form. The protein is present, but not phosphorylated, within the nuclei of myocytes in intact neonatal rat hearts and in high-density cultures. It is not expressed in low-density cultures. Increasing the amount of phosphorylated cyclic AMP with either isoproterenol or forskolin also increases the frequency and force of the beating. The phosphorylated form of the response element binding protein is visible in the nuclei by 10 min and persists for 2 h of drug treatment. A 1.5-fold increase in skeletal alpha-actin and alpha-myosin gene expression is detected after 48 h of isoproterenol treatment. However, blockage of beating with a calcium channel blocker (verapamil) in the presence of cyclic AMP results in a similar increased gene expression. This suggests that muscle gene expression can be regulated directly by the cyclic AMP pathway, probably via phosphorylation of the cyclic AMP response element binding protein but independent of contractile activity.
Author List
Goldspink PH, Russell BMESH terms used to index this publication - Major topics in bold
ActinsAnimals
Animals, Newborn
Base Sequence
Biomarkers
Blotting, Northern
Cells, Cultured
Cyclic AMP
Cyclic AMP Response Element-Binding Protein
Gene Expression Regulation
Immunohistochemistry
Muscle Contraction
Muscle Fibers, Skeletal
Myocardium
Myosins
Phosphorylation
Rats
Rats, Sprague-Dawley
Receptors, Adrenergic, beta
Signal Transduction