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[Calcium-dependent regulation of cardiac adenyl cyclase by calmodulin].
- Source :
-
Biulleten' Vsesoiuznogo kardiologicheskogo nauchnogo tsentra AMN SSSR [Biull Vsesoiuznogo Kardiol Nauchn Tsentra AMN SSSR] 1984; Vol. 7 (1), pp. 31-40. - Publication Year :
- 1984
-
Abstract
- Calmodulin (CM) was found to activate adenylate cyclase (AC) in plasma membrane preparations of the rabbit heart in the presence of micromolar Ca2+ concentrations. CM action on the enzyme is terminated by trifluoperazine, troponin I and high Ma2 +/Ca2+ ratio. Isoproterenol in the presence of GTP, guanosine-5'-beta-gamma-imidotriphosphate[Cpp(NH)p] and sodium fluoride increases CM-dependent heart AC activity without changing the enzyme affinity to CM and Ca ions. CM has no effect on the convertion of regulatory N-protein into Gpp(NH)p-activated state. CM action on AC is revealed only if catalytic subunit forms a complex with regulatory N-protein. The conclusion was drawn that there is no distinct CM-dependent AC form in the heart, but the same catalytic subunit of the enzyme is regulated both by N-protein and CM. In the presence of Ca2+ and guanye nucleotides AC of the heart exists in the form of a complex: CM-catalytic subunit-N-protein.
- Subjects :
- Animals
GTP-Binding Proteins
Guanosine Triphosphate pharmacology
Guanylyl Imidodiphosphate pharmacology
In Vitro Techniques
Isoproterenol pharmacology
Magnesium physiology
Rabbits
Receptors, Cell Surface physiology
Sarcolemma enzymology
Sodium Fluoride pharmacology
Adenylyl Cyclases metabolism
Calcium physiology
Calmodulin physiology
Myocardium enzymology
Subjects
Details
- Language :
- Russian
- ISSN :
- 0201-7369
- Volume :
- 7
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Biulleten' Vsesoiuznogo kardiologicheskogo nauchnogo tsentra AMN SSSR
- Publication Type :
- Academic Journal
- Accession number :
- 6329245