Functional reconstitution of skeletal muscle Ca sup 2+ channels: Separation of regulatory and channel components

Journal Article · Wed Jun 01 04:00:00 EDT 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.11.3718· OSTI ID:5565442

Horne, W A; Abdel-Ghany, M; Racker, E; Weiland, G A; Oswald, R E; Cerione, R A ^[1]

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1. Cornell Univ., Ithaca, NY (USA)

Regulatory properties of a partially purified Ca{sup 2+}-channel preparation from isolated rabbit skeletal muscle triads were examined in proteoliposomes. By selective reconstitution of protein fractions obtained by wheat germ lectin and ion-exchange chromatography, a separation of Ca{sup 2+}-channel activity (fraction C) from regulatory component(s) (fraction R) responsible for verapamil sensitivity was achieved. Reconstitution of fraction C alone yielded vesicles that exhibited channel-mediated {sup 45}Ca{sup 2+} uptake that could be directly inhibited by coreconstitution of G{sub 0} in the presence of guanosine 5{prime}-({gamma}-thio)triphosphate. Coreconstitution of fractions C and R yielded vesicles in which the sensitivity of {sup 45}Ca{sup 2+} uptake to verapamil was restored. Fraction C included a 180-kDa protein that was phosphorylated by cAMP-dependent protein kinase (PK-A) but not by PK-P and a 145-kDa protein that was not phosphorylated by either kinase. Fraction R contained proteins that did not absorb to wheat germ lectin and included 165-kDa and 55-kDa proteins that were phosphorylated by PK-P but not by PK-A. These results suggest a complex model for Ca{sup 2+}-channel regulation in skeletal muscle involving a number of distinct, separable protein components.

• OSTI ID: 5565442
• 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. 85:11; ISSN PNASA; ISSN 0027-8424
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMISTRY
CALCIUM 45
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM HALIDES
CALCIUM ISOTOPES
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
ELECTROPHORESIS
ENZYMES
EVEN-ODD NUCLEI
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
IONS
ISOTOPES
LIQUID COLUMN CHROMATOGRAPHY
MAMMALS
MEMBRANE TRANSPORT
MUSCLES
NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PHYSIOLOGY
PROTEINS
RABBITS
RADIOISOTOPES
SEPARATION PROCESSES
TRANSFERASES
TRITIUM COMPOUNDS
UPTAKE
VERTEBRATES