title: Circadian control of the NAD+ salvage pathway by CLOCK-SIRT1.
abstract: Many metabolic and physiological processes display circadian oscillations. We have shown that the core circadian regulator, CLOCK, is a histone acetyltransferase whose activity is counterbalanced by the nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase SIRT1. Here we show that intracellular NAD+ levels cycle with a 24-hour rhythm, an oscillation driven by the circadian clock. CLOCK:BMAL1 regulates the circadian expression of NAMPT (nicotinamide phosphoribosyltransferase), an enzyme that provides a rate-limiting step in the NAD+ salvage pathway. SIRT1 is recruited to the Nampt promoter and contributes to the circadian synthesis of its own coenzyme. Using the specific inhibitor FK866, we demonstrated that NAMPT is required to modulate circadian gene expression. Our findings in mouse embryo fibroblasts reveal an interlocked transcriptional-enzymatic feedback loop that governs the molecular interplay between cellular metabolism and circadian rhythms.
authors.affiliation: Department of Pharmacology, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA.
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Nakahata
authors.forename: Saurabh
authors.initials: S
authors.lastname: Sahar
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Astarita
authors.forename: Milota
authors.initials: M
authors.lastname: Kaluzova
authors.forename: Paolo
authors.initials: P
authors.lastname: Sassone-Corsi
mesh_terms: D056930:ARNTL Transcription Factors; D000178:Acrylamides / Q000494:pharmacology; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D001683:Biological Clocks; D056926:CLOCK Proteins; D002460:Cell Line; D042002:Chromatin Assembly and Disassembly; D002940:Circadian Rhythm; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D025461:Feedback, Physiological; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009243:NAD / Q000378:metabolism*; D009536:Niacinamide / Q000378:metabolism; D054409:Nicotinamide Phosphoribosyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D056564:Sirtuin 1; D037761:Sirtuins / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D056930:ARNTL Transcription Factors; D000178:Acrylamides; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D016207:Cytokines; D004791:Enzyme Inhibitors; D009243:NAD; D009536:Niacinamide; D054409:Nicotinamide Phosphoribosyltransferase; D010880:Piperidines; D056564:Sirtuin 1; D037761:Sirtuins; D015534:Trans-Activators; C538961:Bmal1 protein, mouse; C480543:N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide; C538944:Clock protein, mouse; C495867:nicotinamide phosphoribosyltransferase, mouse; C470545:Sirt1 protein, mouse