Characterization of a major protein in GLUT4 vesicles. Concentration in the vesicles and insulin-stimulated translocation to the plasma membrane.
GLUT4-enriched vesicles from fat and muscle cells contain a major protein of 165 kDa. In the present study we have prepared GLUT4 vesicles from a large number of rat adipocytes, isolated the 165-kDa protein by SDS-gel electrophoresis, and obtained the sequences of four tryptic peptides. Comparison of the sequences with those in protein data banks showed that the 165-kDa protein had not previously been sequenced. An antibody preparation against one of the peptides immunoblotted the 165-kDa protein. By this means it was found that the 165-kDa protein was concentrated in GLUT4 vesicles, and that insulin treatment of rat adipocytes caused a translocation of the protein to the plasma membrane that paralleled the translocation of GLUT4.
Mastick
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CC
Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755.
Aebersold
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R
Lienhard
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GE
D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009124:Muscle Proteins; D010455:Peptides / Q000378:metabolism; D011506:Proteins / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013347:Subcellular Fractions / Q000378:metabolism
D000906:Antibodies; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D010455:Peptides; D011506:Proteins; C495694:Slc2a4 protein, rat