Insulin stimulates the halting, tethering, and fusion of mobile GLUT4 vesicles in rat adipose cells.
J Cell Biol
; 169(3): 481-9, 2005 May 09.
Article
em En
| MEDLINE
| ID: mdl-15866888
ABSTRACT
Glucose transport in adipose cells is regulated by changing the distribution of glucose transporter 4 (GLUT4) between the cell interior and the plasma membrane (PM). Insulin shifts this distribution by augmenting the rate of exocytosis of specialized GLUT4 vesicles. We applied time-lapse total internal reflection fluorescence microscopy to dissect intermediates of this GLUT4 translocation in rat adipose cells in primary culture. Without insulin, GLUT4 vesicles rapidly moved along a microtubule network covering the entire PM, periodically stopping, most often just briefly, by loosely tethering to the PM. Insulin halted this traffic by tightly tethering vesicles to the PM where they formed clusters and slowly fused to the PM. This slow release of GLUT4 determined the overall increase of the PM GLUT4. Thus, insulin initially recruits GLUT4 sequestered in mobile vesicles near the PM. It is likely that the primary mechanism of insulin action in GLUT4 translocation is to stimulate tethering and fusion of trafficking vesicles to specific fusion sites in the PM.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Transporte de Monossacarídeos
/
Tecido Adiposo
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Adipócitos
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Vesículas Transportadoras
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Glucose
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Insulina
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Proteínas Musculares
Limite:
Animals
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article