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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
17
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pubmed:dateCreated |
1991-10-3
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pubmed:abstractText |
Previous studies indicated that the erythroidtype (GLUT1) glucose transporter isoform contributes to basal but not insulin-stimulated hexose transport in mouse 3T3-L1 adipocytes. In the present studies it was found that basal hexose uptake in 3T3-L1 adipocytes was about 50% lower than that in 3T3-L1 or CHO-K1 fibroblasts. Intrinsic catalytic activities of GLUT1 transporters in CHO-K1 and 3T3-L1 cells were compared by normalizing these hexose transport rates to GLUT1 content on the cell surface, as measured by two independent methods. Cell surface GLUT1 levels in 3T3-L1 fibroblasts and adipocytes were about 10- and 25-fold higher, respectively, than in CHO-K1 fibroblasts, as assessed with an anti-GLUT1 exofacial domain antiserum, delta. The large excess of cell surface GLUT1 transporters in 3T3-L1 adipocytes relative to CHO-K1 fibroblasts was confirmed by GLUT1 protein immunoblot analysis and by photoaffinity labelling (with 3-[125I]iodo-4-azidophenethylamido-7-O-succinyldeacetylforskoli n) of glucose transporters in isolated plasma membranes. Thus, GLUT1 intrinsic activity is markedly reduced in 3T3-L1 fibroblasts compared with the CHO-K1 fibroblasts, and further reduction occurs upon differentiation to adipocytes. Intrinsic catalytic activities specifically associated with heterologously expressed human GLUT1 protein in transfected CHO-K1 versus 3T3-L1 cells were determined by subtracting appropriate control cell values for hexose transport and delta-antibody binding from those determined in the transfected cells expressing high levels of human GLUT1. The results confirmed a greater than 90% inhibition of the intrinsic catalytic activity of human GLUT1 transporters on the surface of mouse 3T3-L1 adipocytes relative to CHO-K1 fibroblasts. We conclude that a mechanism that markedly suppresses basal hexose transport catalyzed by GLUT1 is a major contributor to the dramatic insulin sensitivity of glucose uptake in 3T3-L1 adipocytes.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2037570,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2156829,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2165064,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2173694,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2211693,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2217557,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2407477,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2536700,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2545707,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2644284,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2645527,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2649253,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2654938,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-2682625,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3029870,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3063259,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3137219,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3276714,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3285221,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3301853,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3525539,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3527041,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3693367,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3718945,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3733703,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-3733746,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1881918-5432063
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0027-8424
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
88
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
7839-43
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:1881918-3-O-Methylglucose,
pubmed-meshheading:1881918-Adipose Tissue,
pubmed-meshheading:1881918-Affinity Labels,
pubmed-meshheading:1881918-Animals,
pubmed-meshheading:1881918-Antibodies,
pubmed-meshheading:1881918-Azides,
pubmed-meshheading:1881918-Cell Line,
pubmed-meshheading:1881918-Cell Membrane,
pubmed-meshheading:1881918-Deoxyglucose,
pubmed-meshheading:1881918-Fibroblasts,
pubmed-meshheading:1881918-Forskolin,
pubmed-meshheading:1881918-Insulin,
pubmed-meshheading:1881918-Kinetics,
pubmed-meshheading:1881918-Methylglucosides,
pubmed-meshheading:1881918-Mice,
pubmed-meshheading:1881918-Monosaccharide Transport Proteins
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pubmed:year |
1991
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pubmed:articleTitle |
Suppressed intrinsic catalytic activity of GLUT1 glucose transporters in insulin-sensitive 3T3-L1 adipocytes.
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pubmed:affiliation |
Program in Molecular Medicine, University of Massachusetts Medical Center, Worcester 01605.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.
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