Ca(2+) and insulin-mediated glucose uptake.
Insulin stimulates glucose uptake in striated muscle and fat via a complex cascade of signaling events. Insulin resistance in these tissues and type 2 diabetes constitute major and rapidly increasing health problems in society. Recent research implicates an important role of Ca(2+) in insulin-mediated glucose uptake. Maneuvers that increase or decrease Ca(2+) influx also increase or decrease insulin-mediated glucose uptake both in normal and insulin-resistant cells. Ca(2+) appears to act on late steps in the insulin-signaling cascade, that is, the docking and fusion of glucose transporter 4 (GLUT4) vesicles with the plasma membrane. No Ca(2+) sensor in this process has yet been explicitly identified but recent studies point at synaptotagmin VII and the motor protein Myo1c as possible candidates.
Lanner
Johanna T
JT
Department of Physiology & Pharmacology, Karolinska Institutet, S-171 77 Stockholm, Sweden. johanna.lanner@ki.se
Bruton
Joseph D
JD
Katz
Abram
A
Westerblad
Håkan
H
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D004075:Diglycerides / Q000494:pharmacology; D005089:Exocytosis; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000187:drug effects; D021381:Protein Transport
D004075:Diglycerides; D051275:Glucose Transporter Type 4; D007328:Insulin; D005947:Glucose; D002118:Calcium