SREBP-1 as a transcriptional integrator of circadian and nutritional cues in the liver.
The act of feeding in mammals can generate such powerful cues for peripheral organs that, under certain conditions, they can override the entraining signals coming from the clock in the brain. Restricting the feeding time to the inactivity period, for example, can completely and quickly reverse the rhythms of gene expression in the liver. This manipulation does not affect the central oscillator in the suprachiasmatic nucleus, which is phase-locked to the light-dark cycle, but does release the peripheral oscillations in the liver from central control. It seems reasonable to predict the existence of one or more immediate response systems designed to sense the need to acutely reverse the sequence of absorptive and postabsorptive phases in the liver. In this study, the authors monitored the posttranslational activation of the sterol response element binding proteins from a circadian point of view to evaluate the role they might play in the circadian organization of the liver transcriptome as well as in the reversal of hepatic physiology that accompanies diurnal restricted feeding. This study highlights a possible direct link between the immediate effects of food consumption on the level of key membrane and humoral factors and the expression status of a set of coordinately regulated target genes in the liver.
Brewer
Michelle
M
Unit on Temporal Gene Expression, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA.
Lange
David
D
Baler
Ruben
R
Anzulovich
Ana
A
D000818:Animals; D015152:Blotting, Northern; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics* / Q000502:physiology*; D002784:Cholesterol / Q000096:biosynthesis; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology*; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D008055:Lipids / Q000096:biosynthesis; D008099:Liver / Q000378:metabolism / Q000502:physiology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009747:Nutritional Physiological Phenomena / Q000502:physiology*; D011499:Protein Processing, Post-Translational; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012727:Sex Characteristics; D015398:Signal Transduction / Q000235:genetics; D013217:Starvation / Q000235:genetics / Q000523:psychology; D051780:Sterol Regulatory Element Binding Protein 1; D051782:Sterol Regulatory Element Binding Protein 2; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology*
D022762:CCAAT-Enhancer-Binding Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D008055:Lipids; C497388:Srebf1 protein, mouse; C497391:Srebf2 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1; D051782:Sterol Regulatory Element Binding Protein 2; D014157:Transcription Factors; D002784:Cholesterol