Intestinal hexose absorption and gluconeogenesis have been studied in relation to refeeding after two different fasting phases: a long period of protein sparing during which energy expenditure is derived from lipid oxidation (phase II), and a later phase characterized by a rise in plasma corticosterone triggering protein catabolism (phase III). Such a switch in body fuel uses, leading to change...

Cyclic-AMP stabilizes phosphoenolpyruvate carboxykinase (GTP) (PEPCK) mRNA against degradation. To investigate the mechanism of this effect, RNA mobility shift assays were used to determine the interaction of cellular proteins with specific domains from the mRNA. We report here the identification of a protein with an affinity for sequences of PEPCK mRNA with a predicted stem-loop structure. RNA...

A cluster of inter-related conditions such as central obesity, dyslipidemia, impaired glucose metabolism, and hypertension is referred to as Metabolic Syndrome, which is a risk factor for the development of type-2 diabetes. The micro- and macro-vascular complications of diabetes contribute to its morbidity and mortality. In addition to its calcitropic effect, vitamin D is a regulator of gene ex...

BACKGROUND: The liver has been suggested as a suitable target organ for gene therapy of Type 1 diabetes. However, the fundamental issue whether insulin-secreting hepatocytes in vivo will be destroyed by the autoimmune processes that kill pancreatic beta cells has not been fully addressed. It is possible that the insulin secreting liver cells will be destroyed by the immune system because hepato...

C4 photosynthesis has higher light-use, nitrogen-use, and water-use efficiencies than C3 photosynthesis. Historically, most of C4 plants were classified into three subtypes (NADP-malic enzyme (ME), NAD-ME, or phosphoenolpyruvate carboxykinase (PEPCK) subtypes) according to their major decarboxylation enzyme. However, a wealth of historic and recent data indicates that flexibility exists between...

Liver-specific phosphoenolpyruvate carboxykinase (PEPCK) null mice, when fasted, maintain normal whole body glucose kinetics but develop dramatic hepatic steatosis. To identify the abnormalities of hepatic energy generation that lead to steatosis during fasting, we studied metabolic fluxes in livers lacking hepatic cytosolic PEPCK by NMR using 2H and 13C tracers. After a 4-h fast, glucose produ...

Cyclic AMP treatment of hepatoma cells leads to increased protein binding at the cyclic AMP response element (CRE) of the tyrosine aminotransferase (TAT) gene in vivo, as revealed by genomic footprinting, whereas no increase is observed at the CRE of the phosphoenolpyruvate carboxykinase (PEPCK) gene. Several criteria establish that the 43 kDa CREB protein is interacting with both of these site...

The metabolic effects of Roux-en-Y gastric bypass (RYGB) are caused by postsurgical changes in gastrointestinal anatomy affecting gut function. Glutamine is a critical gut nutrient implicated in regulating glucose metabolism as a substrate for intestinal gluconeogenesis. The present study examines the effects of obesity and RYGB on intestinal glutamine transport and metabolism. First, lean and ...

Fatty acid translocase (FAT)/CD36 has been extensively studied for its role in facilitating fatty acid uptake. Recent findings have also demonstrated that this protein regulates adipocyte lipolysis and may modulate fatty acid reesterification. As FAT/CD36 has been shown to control the expression of genes involved in fatty acid oxidation in adipocytes, we reasoned that this protein might also co...