Isoproterenol stimulates phosphorylation of the insulin-regulatable glucose transporter in rat adipocytes

Journal Article · Tue Oct 31 23:00:00 EST 1989 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.86.21.8368· OSTI ID:6906576

James, D E; Hiken, J; Lawrence, Jr, J C ^[1]

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1. Washington Univ. School of Medicine, St. Louis, MO (USA)

The authors have examined the acute effect of insulin and isoproterenol on the phosphorylation state of the insulin-regulatable glucose transporter (IRGT) in rat adipocytes. The IRGT was immunoprecipitated from either detergent-solubilized whole-cell homogenates or subcellular fraction of {sup 32}P-labeled fat cells and subjected to sodium dodecyl sulfate/polyarcylamide gel electrophoresis. The {sup 32}P-labeled IRGT was detected by autoradiography as a species of apparent M{sub r} 46,000. Insulin stimulated translocation of the IRGT from low-density microsomes to the plasma membrane but did not affect phosphorylation of the transporter in either fraction. Isoproterenol inhibited insulin-stimulated glucose transport by 40% but was without effect on the subcellar distribution of the transporter in either the presence or absence of insulin. Isoproterenol stimulated phosphorylation of the IRGT 2-fold. Incubating cells with dibutyryl-cAMP and 8-bromo-cAMP also stimulated phosphorylation 2-fold, and the transporter was phosphorylated in vitro when IRGT-enriched vesicles were incubated with cAMP-dependent protein kinase and ({gamma}-{sup 32}P)ATP. These results suggest that isoproterenol stimulates phosphorylation of the IRGT via a cAMP-dependent pathway and that phosphorylation of the transporter may modulate its ability to transport glucose.

• OSTI ID: 6906576
• 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. 86:21; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADIPOSE TISSUE
ALDEHYDES
AMINES
ANIMAL CELLS
ANIMAL TISSUES
AROMATICS
ATP
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BODY
CARBOHYDRATES
CATECHOLAMINES
CHEMICAL REACTIONS
CONNECTIVE TISSUE
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTROPHORESIS
FAT CELLS
GLUCOSE
HEXOSES
HORMONES
HYDROXY COMPOUNDS
INSULIN
ISOTOPES
LIGHT NUCLEI
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MONOSACCHARIDES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHENOLS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORYLATION
POLYPHENOLS
PROTEINS
RADIOISOTOPES
SACCHARIDES
SOMATIC CELLS
TISSUES