Staurosporine as an agonist for induction of GLUT4 translocation, identified by a pH-sensitive fluorescent IRAP-mOrange2 probe

Abstract

Insulin-stimulated GLUT4 translocation from GLUT4 storage vesicles (GSVs) to the plasma membrane (PM) constitutes a key process for blood glucose control. Therefore, compounds that could promote GLUT4 translocation into the PM represent potential drugs for the treatment of diabetes. In this research, we screened for agonists that induce GLUT4 translocation by using a novel pH-sensitive fluorescent probe, insulin-regulated aminopeptidase (IRAP)-mOrange2. We identified as well as validated one agonist, staurosporine, from a 64,000 compound library. Staurosporine promotes GSVs translocation into the PM and increases glucose uptake through the AMP-activated protein kinase (AMPK) pathway, serving as an effective insulin additive analogue in L6 cells. Our work highlights the convenience and efficiency of this novel pH-sensitive fluorescent probe and reveals the new biological activity of staurosporine as an agonist for GLUT4 translocation and as an effective insulin additive analogue.