Monensin and Proinsulin Biosynthesis
نویسنده
چکیده
Monensin, a specific sodium ionophore~ has been shown to reduce glucose-induced proinsulin biosynthesis by 30% and to completely inhibit ~he intracellular conversion of proinsul in to insulin. Autoradiography of monensint r e a t e d cells d e m o n s t r a t e d the p resence of large quantities of newly synthesized proteins in amorphous vesicles close to the Golgi complex of B ceils. The r e s u l t s sugges t profound e f f e c t s of monensin on biosynthesis and intracellular processing of proinsulin.
منابع مشابه
Insulin does not mediate glucose stimulation of proinsulin biosynthesis.
It has recently been suggested that insulin augments its own production by a physiologically important feed-forward autocrine loop. We studied the kinetics of glucose-regulated proinsulin gene expression and proinsulin biosynthesis in normal rat islets with emphasis on the potential role of insulin as a mediator of the glucose effect. There was a time-dependent increase in steady-state proinsul...
متن کاملSuccinate is a preferential metabolic stimulus-coupling signal for glucose-induced proinsulin biosynthesis translation.
The secondary signals emanating from increased glucose metabolism, which lead to specific increases in proinsulin biosynthesis translation, remain elusive. It is known that signals for glucose-stimulated insulin secretion and proinsulin biosynthesis diverge downstream of glycolysis. Consequently, the mitochondrial products ATP, Krebs cycle intermediates, glutamate, and acetoacetate were investi...
متن کاملRegulation of the production and secretion of insulin
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متن کاملGlucose-induced translational control of proinsulin biosynthesis is proportional to preproinsulin mRNA levels in islet beta-cells but not regulated via a positive feedback of secreted insulin.
Proinsulin biosynthesis is regulated in response to nutrients, most notably glucose. In the short term (</=2h) this is due to increases in the translation of pre-existing mRNA. However, prolonging glucose stimulation (24 h) also increases preproinsulin mRNA levels. It has been proposed that secreted insulin from the pancreatic beta-cell regulates its own synthesis through a positive autocrine f...
متن کاملA distinct difference in the metabolic stimulus-response coupling pathways for regulating proinsulin biosynthesis and insulin secretion that lies at the level of a requirement for fatty acyl moieties.
The regulation of proinsulin biosynthesis in pancreatic beta-cells is vital for maintaining optimal insulin stores for glucose-induced insulin release. The majority of nutrient fuels that induce insulin release also stimulate proinsulin biosynthesis, but since insulin exocytosis and proinsulin synthesis involve different cellular mechanisms, a point of divergence in the respective metabolic sti...
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تاریخ انتشار 2005