The glucose-sensing transcription factor ChREBP is targeted by proline hydroxylation.

Cellular energy demands are met by uptake and metabolism of nutrients like glucose. The principal transcriptional regulator for adapting glycolytic flux and downstream pathways like lipogenesis to glucose availability in many cell types is carbohydrate response element-binding protein (ChREBP). ChREBP is activated by glucose metabolites and post-translational modifications, inducing nuclear accumulation and regulation of target genes.

Liver-secreted RBP4 does not impair glucose homeostasis in mice.

Retinol-binding protein 4 (RBP4) is the major transport protein for retinol in blood. Recent evidence from genetic mouse models shows that circulating RBP4 derives exclusively from hepatocytes. Because RBP4 is elevated in obesity and associates with the development of glucose intolerance and insulin resistance, we tested whether a liver-specific overexpression of RBP4 in mice impairs glucose homeostasis.

Reciprocal regulation of carbon monoxide metabolism and the circadian clock.

Circadian clocks are cell-autonomous oscillators regulating daily rhythms in a wide range of physiological, metabolic and behavioral processes. Feedback of metabolic signals, such as redox state, NAD/NADH and AMP/ADP ratios, or heme, modulate circadian rhythms and thereby optimize energy utilization across the 24-h cycle. We show that rhythmic heme degradation, which generates the signaling molecule carbon monoxide (CO), is required for normal circadian rhythms as well as circadian metabolic outputs.

Liver p53 is stabilized upon starvation and required for amino acid catabolism and gluconeogenesis.

The ability to adapt cellular metabolism to nutrient availability is critical for survival. The liver plays a central role in the adaptation to starvation by switching from glucose-consuming processes and lipid synthesis to providing energy substrates like glucose to the organism. Here we report a previously unrecognized role of the tumor suppressor p53 in the physiologic adaptation to food withdrawal.

The Glucose Sensor ChREBP Links De Novo Lipogenesis to PPARγ Activity and Adipocyte Differentiation.

Reduced de novo lipogenesis in adipose tissue, often observed in obese individuals, is thought to contribute to insulin resistance. Besides trapping excess glucose and providing for triglycerides and energy storage, endogenously synthesized lipids can function as potent signaling molecules. Indeed, several specific lipids and their molecular targets that mediate insulin sensitivity have been recently identified.