Regulation of small GTP-binding proteins by insulin.
Several members of the extensive family of small GTP-binding proteins are regulated by insulin, and have been implicated in insulin action on glucose uptake. These proteins are themselves negatively regulated by a series of specific GAPs (GTPase-activating proteins). Interestingly, there is increasing evidence to suggest that PKB (protein kinase B)-dependent phosphorylation of some GAPs may relieve this negative regulation and so lead to the activation of the target small GTP-binding protein. We review recent evidence that this may be the case, and place specific emphasis on the role of these pathways in insulin-stimulated glucose uptake.
Welsh
G I
GI
Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 ITD, UK.
Hers
I
I
Wherlock
M
M
Tavaré
J M
JM
D000818:Animals; D007328:Insulin / Q000494:pharmacology*; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
D007328:Insulin; D051057:Proto-Oncogene Proteins c-akt; D020559:Monomeric GTP-Binding Proteins