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Immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat
Antibodies specific for the insulin-regulatable glucose transporter (GLUT 4) were used to immunolocalize this protein in brown adipose tissue from basal- and insulin-treated rats. Cryosections of fixed tissue were incubated with antibodies, which were subsequently labeled with Protein A/gold and exa...
Formato: | Texto |
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Lenguaje: | English |
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The Rockefeller University Press
1991
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2288909/ https://www.ncbi.nlm.nih.gov/pubmed/2007617 |
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collection | PubMed |
description | Antibodies specific for the insulin-regulatable glucose transporter (GLUT 4) were used to immunolocalize this protein in brown adipose tissue from basal- and insulin-treated rats. Cryosections of fixed tissue were incubated with antibodies, which were subsequently labeled with Protein A/gold and examined by EM. Antibodies against albumin and cathepsin D were also used with gold particles of different sizes to identify early and late endosomes, respectively. Under basal conditions 99% of the GLUT 4 labeling was located within the cell. Labeling was predominantly in the trans-Golgi reticulum and tubulo-vesicular structures elsewhere in the cytoplasm. In insulin-stimulated cells approximately 40% of the GLUT 4 labeling was at the cell surface, where it was randomly distributed, except for occasional clustering in coated pits. Moreover, after insulin treatment, GLUT 4 was also enriched in early endosomes. We conclude that translocation of GLUT 4 to the cell surface is the major mechanism by which insulin increases glucose transport. In addition, these results suggest that in the presence of insulin GLUT 4 recycles from the cell surface, probably via the coated pit-endosome pathway that has been characterized for cell surface receptors, and also that insulin causes the redistribution of GLUT 4 by stimulating exocytosis from GLUT 4-containing tubulo-vesicular structures, rather than by slowing endocytosis of GLUT 4. |
format | Text |
id | pubmed-2288909 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1991 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22889092008-05-01 Immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat J Cell Biol Articles Antibodies specific for the insulin-regulatable glucose transporter (GLUT 4) were used to immunolocalize this protein in brown adipose tissue from basal- and insulin-treated rats. Cryosections of fixed tissue were incubated with antibodies, which were subsequently labeled with Protein A/gold and examined by EM. Antibodies against albumin and cathepsin D were also used with gold particles of different sizes to identify early and late endosomes, respectively. Under basal conditions 99% of the GLUT 4 labeling was located within the cell. Labeling was predominantly in the trans-Golgi reticulum and tubulo-vesicular structures elsewhere in the cytoplasm. In insulin-stimulated cells approximately 40% of the GLUT 4 labeling was at the cell surface, where it was randomly distributed, except for occasional clustering in coated pits. Moreover, after insulin treatment, GLUT 4 was also enriched in early endosomes. We conclude that translocation of GLUT 4 to the cell surface is the major mechanism by which insulin increases glucose transport. In addition, these results suggest that in the presence of insulin GLUT 4 recycles from the cell surface, probably via the coated pit-endosome pathway that has been characterized for cell surface receptors, and also that insulin causes the redistribution of GLUT 4 by stimulating exocytosis from GLUT 4-containing tubulo-vesicular structures, rather than by slowing endocytosis of GLUT 4. The Rockefeller University Press 1991-04-01 /pmc/articles/PMC2288909/ /pubmed/2007617 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Articles Immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat |
title | Immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat |
title_full | Immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat |
title_fullStr | Immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat |
title_full_unstemmed | Immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat |
title_short | Immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat |
title_sort | immuno-localization of the insulin regulatable glucose transporter in brown adipose tissue of the rat |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2288909/ https://www.ncbi.nlm.nih.gov/pubmed/2007617 |