Activation of purified calcium channels by stoichiometric protein phosphorylation

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.86.17.6816· OSTI ID:5481922

Nunoki, K; Florio, V; Catterall, W A ^[1]

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1. Univ. of Washington, Seattle (USA)

Purified dihydropyridine-sensitive calcium channels from rabbit skeletal muscle were reconstituted into phosphatidylcholine vesicles to evaluate the effect of phosphorylation by cyclic AMP-dependent protein kinase (PK-A) on their function. Both the rate and extent of {sup 45}Ca{sup 2+} uptake into vesicles containing reconstituted calcium channels were increased severalfold after incubation with ATP and PK-A. The degree of stimulation of {sup 45}Ca{sup 2+} uptake was linearly proportional to the extent of phosphorylation of the alpha 1 and beta subunits of the calcium channel up to a stoichiometry of approximately 1 mol of phosphate incorporated into each subunit. The calcium channels activated by phosphorylation were determined to be incorporated into the reconstituted vesicles in the inside-out orientation and were completely inhibited by low concentrations of dihydropyridines, phenylalkylamines, Cd{sup 2+}, Ni{sup 2+}, and Mg{sup 2+}. The results demonstrate a direct relationship between PK-A-catalyzed phosphorylation of the alpha 1 and beta subunits of the purified calcium channel and activation of the ion conductance activity of the dihydropyridine-sensitive calcium channels.

• OSTI ID: 5481922
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 86:17; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ANIMALS
ATP
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL FUNCTIONS
CALCIUM
CALCIUM 45
CALCIUM ISOTOPES
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ELEMENTS
ENZYME INHIBITORS
ENZYMES
ESTERS
EVEN-ODD NUCLEI
FRACTIONATION
FUNCTIONS
INTERMEDIATE MASS NUCLEI
IONS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIPIDS
MAMMALS
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
METALS
MUSCLES
NUCLEI
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PORINS
PROTEINS
RABBITS
RADIOISOTOPES
REACTION KINETICS
SEPARATION PROCESSES
STOICHIOMETRY
TRACER TECHNIQUES
TRANSFERASES
VERTEBRATES