G/sub o/ protein of fat cells: role in hormonal regulation of agonist-stimulated phosphatidyl inositol breakdown
Incubating rat fat cell membranes in the presence of (/sup 32/P)NAD/sup +/ and pertussis toxin (PT) results in the ADP-ribosylation of two peptides (M/sub r/ = 41,000 and 40,000). The 41,000-M/sub r/ peptide is the inhibitory G-protein of adenylate cyclase (G/sub i/). The 40,000-M/sub r/ peptide radiolabeled in the presence of (/sup 32/P)NAD/sup +/ and PT has been purified from rabbit heart and bovine brain, but has not been identified uniformly in membranes of fat cells. Two rabbit polyclonal antisera raised against the alpha-subunit of bovine brain G/sub o/ were used to probe the nature of the 40,000-M/sub r/ peptide in rat fat cell membranes that had been separated by gel electrophoresis in the presence of sodium dodecyl sulfate and transferred electrophoretically to nitrocellulose. Both antisera specific for the alpha-subunit of G/sub o/ recognized the M/sub r/ = 40,000 peptide of fat cells that is ADP-ribosylated in the presence of PT. PT treatment of rat fat cells blocks epinephrine-stimulated inositol 1,4,5 trisphosphate (IP/sub 3/) generation. The inhibition of IP/sub 3/ generation by PT suggests a role for either G/sub i/ or G/sub o/ in receptor-mediated phosphatidyl inositol breakdown in the rat fat cell.
- Research Organization:
- State Univ. of New York, Stony Brook
- OSTI ID:
- 5326873
- Report Number(s):
- CONF-8606151-; TRN: 86-031389
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
FAT CELLS
CHEMICAL COMPOSITION
INOSITOL
METABOLISM
PEPTIDES
LABELLING
BRAIN
CATTLE
CELL MEMBRANES
ELECTROPHORESIS
NAD
PHOSPHORUS 32
RATS
TOXINS
TRACER TECHNIQUES
ANIMAL CELLS
ANIMALS
ANTIGENS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
COENZYMES
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
INOSITOLS
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MATERIALS
MEMBRANES
MONOSACCHARIDES
NERVOUS SYSTEM
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHOSPHORUS ISOTOPES
PROTEINS
RADIOISOTOPES
RODENTS
RUMINANTS
SACCHARIDES
SOMATIC CELLS
TOXIC MATERIALS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques