Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 4070-4078 |
| Number of pages | 9 |
| Journal | Journal of Biological Chemistry |
| Volume | 280 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2005 |
Fingerprint
Cite this
Insulin and contraction stimulate exocytosis, but increased AMP-activated protein kinase activity resulting from oxidative metabolism stress slows endocytosis of GLUT4 in cardiomyocytes. / Yang, J; Holman, G D.
In: Journal of Biological Chemistry, Vol. 280, No. 6, 2005, p. 4070-4078.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Insulin and contraction stimulate exocytosis, but increased AMP-activated protein kinase activity resulting from oxidative metabolism stress slows endocytosis of GLUT4 in cardiomyocytes
AU - Yang, J
AU - Holman, G D
N1 - ID number: ISI:000227096600011
PY - 2005
Y1 - 2005
N2 - Stimulations of glucose transport produced by insulin action, contraction, or through a change in cell energy status are mediated by separate signaling pathways. These are the wortmannin-sensitive phosphatidylinositol 3-kinase pathway leading to the intermediate Akt and the wortmannin-insensitive AMP-activated protein kinase (AMPK) pathway. Electrical stimulation of cardiomyocytes produced a rapid, insulin-like, wortmannin-sensitive stimulation of glucose transport activity, but this occurred without extensive activation of Akt. Although AMPK phosphorylation was increased by contraction, this response was not wortmannin-inhibitable and consequently did not correlate with the wortmannin sensitivity of the transport stimulation. Oxidative metabolism stress due to hypoxia or treatment with oligomycin led to increased AMPK activity with a corresponding increase in glucose transport activity. We show here that these separate signaling pathways converge on GLUT4 trafficking at separate steps. The rate of exocytosis of GLUT4 was rapidly stimulated by insulin, but insulin treatment did not alter the endocytosis rate. Like insulin stimulation, electrical stimulation of contraction led to a stimulation of GLUT4 exocytosis without any marked change in endocytosis. By contrast, after oxidative metabolism stress, no stimulation of GLUT4 exocytosis occurred; instead, this treatment led to a reduction in GLUT4 endocytosis.
AB - Stimulations of glucose transport produced by insulin action, contraction, or through a change in cell energy status are mediated by separate signaling pathways. These are the wortmannin-sensitive phosphatidylinositol 3-kinase pathway leading to the intermediate Akt and the wortmannin-insensitive AMP-activated protein kinase (AMPK) pathway. Electrical stimulation of cardiomyocytes produced a rapid, insulin-like, wortmannin-sensitive stimulation of glucose transport activity, but this occurred without extensive activation of Akt. Although AMPK phosphorylation was increased by contraction, this response was not wortmannin-inhibitable and consequently did not correlate with the wortmannin sensitivity of the transport stimulation. Oxidative metabolism stress due to hypoxia or treatment with oligomycin led to increased AMPK activity with a corresponding increase in glucose transport activity. We show here that these separate signaling pathways converge on GLUT4 trafficking at separate steps. The rate of exocytosis of GLUT4 was rapidly stimulated by insulin, but insulin treatment did not alter the endocytosis rate. Like insulin stimulation, electrical stimulation of contraction led to a stimulation of GLUT4 exocytosis without any marked change in endocytosis. By contrast, after oxidative metabolism stress, no stimulation of GLUT4 exocytosis occurred; instead, this treatment led to a reduction in GLUT4 endocytosis.
U2 - 10.1074/jbc.M410213200
DO - 10.1074/jbc.M410213200
M3 - Article
VL - 280
SP - 4070
EP - 4078
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 6
ER -