Part:BBa_K3141001

Use of Biology

Proinsulin is a precursor to insulin biosynthesis which can bind to insulin receptor in the liver membrane, to stimulate livers to convert glucose to glycogen. Injections of proinsulin intravenously in animal or man results in a decrease in blood glucose. This means that proinsulin has similar functions of lowering blood glucose level as insulin. In human body, proinsulin is synthesized in pancreatic βcells to enable the downstream insulin secretion into blood. As the only blood glucose reducer, insulin operates mainly through the regulation of hepatic metabolism for the glucose uptake by lever cells[ Paul M. Titchenell, et al:Unraveling the regulation of Hepatic Metabolism by Insulin. Trends Endocrinol Metab. 2017 Jul;28(7):497-505 ]. When the level of glycogen reduces and the concentration of insulin rises, liver cells start to increase the uptake of glucose, synthesis of glycogen, suppression of hepatic glucose production(HGP), and the induction of the synthesis of fatty acids for energy storage and further utilization[ LinHV, et al.:Hormonal Regulation of Hepatic glucose Production in Health and Disease. Cell Metab.2011;14:9-19].

Characterization

To test the expression efficiency, this gene is transformed into pHY-P43 and is expressioned in B.subtilis.