Effects of GAPDH, PGK and PGAM on Insulin-Stimulated Glucose Transport in 3T3-L1 Adipocytes

Glucose transporter 4 (GLUT4) moves from perinuclear storage regions to the plasma membrane in response to insulin and facilitates glucose uptake. This MQP examined the roles of three proteins (GAPDH, PGK, and PGAM) in glucose uptake and GLUT4 trafficking in 3T3-L1 adipocytes by performing glucose uptake assays on adipocytes in which these proteins were selectively knocked down using RNAi. GLUT4 trafficking was visualized by transfection with Myc-tagged GLUT4-GFP and immunofluorescence. The data indicate no effect by PGK, while PGAM and GAPDH inhibited both glucose uptake and GLUT4 fusion to the plasma membrane. GAPDH may be required for general cellular secretion pathways.