Regulation by glucose of the biosynthesis of PC2, PC3 and proinsulin in (ob/ob) mouse Islets of Langerhans

Abstract
The prohormone convertases PC2 and PC3 have been shown to catalyze the processing of proinsulin to insulin in pancreatic β‐cells. In these studies we have compared the effects of glucose on PC2 and PC3 biosynthesis in freshly isolated islets from normal and hyperglycemic (ob/ob) mice. In contrast to normal islets [Alarcón, et al. (1993) J. Biol. Chem. 268, 4276] the biosynthesis of both PC2 and PC3 is stimulated by glucose, parallel to the stimulation of proinsulin in the (ob/ob) islets. Inhibition of PC2 biosynthesis by glucose in normal islet non β‐cells may obscure stimulation of PC2 biosynthesis in normal islet β‐cells.