Cytosolic [Ca2+] modulates basal GLUT1 activity and plays a permissive role in its activation by metabolic stress and insulin in rat epithelial cells

R. A. Quintanilla, O. H. Porras, J. Castro, L. F. Barros*

*Autor correspondiente de este trabajo

Producción científica: Contribución a una revistaArtículorevisión exhaustiva

29 Citas (Scopus)

Resumen

The aim of this work was to investigate the role of cytosolic free calcium ([Ca2+]c) in the stimulation of GLUT1 by metabolic stress and insulin. Chelation of [Ca2+]c with bapta, introduced in rat liver epithelial Clone 9 cells in the acetoxymethyl (AM) form, decreased their basal rate of 2-deoxyglucose uptake in a dose-dependent fashion. Maximal inhibition at 75 μM bapta was by 38 ± 8% (n = 8). The effect was partially reversed by ionomycin. Basal sugar uptake was also decreased by lowering extracellular [Ca2+] in ionomycin-permeabilized cells. Increasing [Ca2+]c over its resting level of 168 ± 32 (n = 27) had no affect on sugar uptake. Chelation of [Ca2+]c did not change the abundance of surface GLUT1 and had no significant effect on the affinity of GLUT1 for sugars. In addition, calcium chelation abolished the activation of GLUT1 by azide, arsenate, 2,4-dinitrophenol and insulin. However, [Ca2+]c did not increase in the presence of azide. We conclude that [Ca2+]c, near or below its resting level, modulates GLUT1 activity over a considerable range and plays a permissive role in the activation of the carrier by metabolic stress and insulin. (C) 2000 Harcourt Publishers Ltd.

Idioma originalInglés
Páginas (desde-hasta)97-106
Número de páginas10
PublicaciónCell Calcium
Volumen28
N.º2
DOI
EstadoPublicada - 2000
Publicado de forma externa

Áreas temáticas de ASJC Scopus

  • Fisiología
  • Biología molecular
  • Biología celular

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