Metabolism
Tankyrase modulates insulin sensitivity in skeletal muscle cells by regulating the stability of GLUT4 vesicle proteins
Tankyrase 1 and 2, members of the poly(ADP-ribose) polymerase family, have previously been shown to play a role in insulin-mediated glucose uptake in adipocytes. However, their precise mechanism of action, and their role in insulin action in other cell types, such as myocytes, remains elusive. Treatment of differentiated L6 myotubes with the small molecule tankyrase inhibitor XAV939 resulted in insulin resistance as determined by impaired insulin-stimulated glucose uptake. Proteomic analysis of XAV939-treated myotubes identified down-regulation of several glucose transporter GLUT4 storage vesicle (GSV) proteins including RAB10, VAMP8, SORT1, and GLUT4.Kinome Screen Identifies PFKFB3 and Glucose Metabolism as Important Regulators of the Insulin/Insulin-like Growth Factor (IGF)-1 Signaling Pathway
Background: Insulin regulates metabolism via the PI3K/Akt pathway.Results: A kinome siRNA screen identified PFKFB3, a glycolysis regulator, as a modulator of insulin action. Manipulation of PFKFB3 activity or glycolysis affected insulin signaling.Conclusion: Intracellular metabolism modulates important signal transduction pathways.Significance: The novel link between glycolysis and growth factor signaling has important implications for the treatment of metabolic diseases.
