The present invention relates to the identification of ALMS1 as the missing player involved in the regulation of the insulin-mediated glucose uptake through GLUT4 sorting vesicles, and to the down-regulation of ALMS1 by αPKC. Accordingly, the present invention relates to a molecule capable of preventing the binding of αPKC on ALMS1 for use for treating or preventing diabetes, in particular type 2 diabetes. In addition, the present invention relates to a method for identifying molecule capable of preventing the binding of αPKC on ALMS1.