Role of cyclic AMP in rat aortic microsomal phosphorylation and calcium uptake.

R. C. Bhalla, R. C. Webb, D. Singh, T. Brock

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The role of adenosine 3',5'-monophosphate (cyclic AMP)-dependent membrane phosphorylation in the regulation of microsomal calcium transport in rat aortic smooth muscle was studied. Cyclic AMP-dependent protein kinase augmented the phosphorylation of serine residues in a microsomal protein component with a molecular weight of about 44,000 (determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and the majority of 32P incorporation was in serine residue(s). The phosphorylated protein had stability characteristics of a phosphoester. The phosphorylated substrate was not extracted from the trichloroacetic acid (TCA) precipitate with organic solvents or by suspension in hot TCA; and the demonstrated hydroxylamine insensitivity suggested that the substrate was not lipid or nucleic acid. Intrinsic phosphoprotein phosphatase cleaved the labeled phosphate from the cyclic AMP-stimulated microsomes in the first 5 min of incubation. Microsomes phosphorylated in the presence of 1 micron cyclic AMP or 1 micron cyclic AMP plus 0.1 mg/ml protein kinase exhibited enhanced calcium uptake. We suggest that reversible phosphorylation of microsomal membranes may play an important role in the regulation of aortic microsomal calcium transport by cyclic AMP.

Original languageEnglish (US)
Pages (from-to)H508-14
Number of pages7
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume234
Issue number5
StatePublished - May 1 1978

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Cyclic AMP
Phosphorylation
Calcium
Trichloroacetic Acid
Microsomes
Serine
Hydroxylamine
Membranes
Protein Stability
Phosphoprotein Phosphatases
Cyclic AMP-Dependent Protein Kinases
Sodium Dodecyl Sulfate
Adenosine
Protein Kinases
Nucleic Acids
Smooth Muscle
Polyacrylamide Gel Electrophoresis
Suspensions
Molecular Weight
Phosphates

ASJC Scopus subject areas

  • Physiology

Cite this

Role of cyclic AMP in rat aortic microsomal phosphorylation and calcium uptake. / Bhalla, R. C.; Webb, R. C.; Singh, D.; Brock, T.

In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 234, No. 5, 01.05.1978, p. H508-14.

Research output: Contribution to journalArticle

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