Endocrine Abstracts

The endoplasmic reticulum (ER) is a cellular compartment specialized for chaperone-assisted folding and post-translational modification of nascent polypeptides. Disruption of ER homeostasis leads to accumulation of unfolded protein and activation of the unfolded protein response (UPR). The UPR emanates from the ER through activation of three transmembrane sensors, IRE1, PERK, and ATF6. IRE1 is a protein kinase / endoribonuclease that, upon activation, initiates a splicing reac...

Insulin has an important role in the regulation of hepatic metabolism during the nutritional transition from the fasted to the fed state. Insulin inhibits glucose production and activates hepatic glycogen synthesis and lipogenesis. The effect of insulin on the regulation of lipogenesis is mainly transcriptional. Lipogenic gene expression is controlled by SREBP-1c, a transcription factor which is synthetized as a precursor embedded in endoplasmic reticulum membranes and which r...

The endoplasmic reticulum (ER) is a metabolic compartment participating in virtually all anabolic and catabolic branches of cellular metabolism. The redox balance of pyridine nucleotides is a major regulator of the metabolism. Several observations demonstrate their presence in the lumen of the ER. NADPH donates electrons for biosynthetic reactions, biotransformation and antioxidant defense; its reduced state is ensured by NADP+-dependent dehydrogenases. In the ER lu...

It is becoming increasingly evident that pathways exist within the (ER) that can impact upon cellular redox status, glucocorticoid metabolism and glucose homeostasis.Within the ER of the liver, glucose-6-phosphatase (G6Pase) and glucose 6-phosphate (G6P) transporter (G6PT) work together to increase blood glucose concentrations by performing the terminal step in both glycogenolysis and gluconeogenesis. The G6Pase ‘shares’ G6P with hexose-6-phosp...