Structure of Nampt/PBEF/visfatin, a mammalian NAD+ biosynthetic enzyme

Wang, Tao; Zhang, Xiangbin; Bheda, Poonam; Revollo, Javier R.; Imai, Shoichi; Wolberger, Cynthia

doi:10.1038/nsmb1114

Cited by 254 publications

(261 citation statements)

References 16 publications

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“…Conservation of this His in Saccharomyces cerevisae NAPT (1VLP, H232) and human NAMPT [2GVG (11), H247] suggests autophosphorylation of H247 in human NAMPT. This assignment is supported by mutagenesis studies [H247E (15) and H247A (11,15)] where mutants exhibited a lower enzymatic activity. Recent ADP/ATP isotope exchange and thermodynamic experiments with human NAMPT established a high-energy, unstable phosphorylated enzyme intermediate (⌬G°h ydrolysis ϭ Ϫ9.2 kcal mol Ϫ1 ) consistent with a phosphohistidine at H257, but structural evidence has been lacking (6).…”

supporting

confidence: 59%

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A phosphoenzyme mimic, overlapping catalytic sites and reaction coordinate motion for human NAMPT

Burgos

Almo

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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Nicotinamide phosphoribosyltransferase (NAMPT) is highly evolved to capture nicotinamide (NAM) and replenish the nicotinamide adenine dinucleotide (NAD ؉ ) pool during ADP-ribosylation and transferase reactions. ATP-phosphorylation of an active-site histidine causes catalytic activation, increasing NAM affinity by 160,000. Crystal structures of NAMPT with catalytic site ligands identify the phosphorylation site, establish its role in catalysis, demonstrate unique overlapping ATP and phosphoribosyltransferase sites, and establish reaction coordinate motion. NAMPT structures with beryllium fluoride indicate a covalent H247-BeF3 ؊ as the phosphohistidine mimic. Activation of NAMPT by H247-phosphorylation causes stabilization of the enzyme-phosphoribosylpyrophosphate complex, permitting efficient capture of NAM. Reactant and product structures establish reaction coordinate motion for NAMPT to be migration of the ribosyl anomeric carbon from the pyrophosphate leaving group to the nicotinamide-N1 while the 5-phosphoryl group, the pyrophosphate moiety, and the nicotinamide ring remain fixed in the catalytic site.ϩ is an essential cofactor in metabolic redox chemistry. It also functions in DNA repair reactions, poly-and mono-ADPribose polymerases, formation of cyclic ADP-ribose, and the Sirtuins (SIRT) (1-5). These reactions can deplete NAD ϩ by cleaving the N-ribosyl bond to generate free nicotinamide (NAM). Nicotinamide phosphoribosyltransferase (NAMPT; also known as pre-␤ cell colony enhancing factor, PBEF, and visfatin, an adipokine) is designed to efficiently recycle NAM (K m ϭ 5 nM) by reaction with ␣-D-5-phosphoribosyl-1-pyrophosphate (PRPP, Fig. 1) to sustain the pool of NAD ϩ (6).In mammals, NAMPT is the rate-limiting enzyme for NAD ϩ salvage from NAM and its overexpression increased cell lifespan (7) via activation of SIRT1 (8). Recently, NAMPT was also identified as the enzyme regulating mitochondrial NAD ϩ levels (9) and extending cell lifespan via the functions of SIR3 and SIR4. Because of its role in NAD ϩ maintenance, NAMPT is a target in cancer research (10). Its inhibition by FK866 causes depletion of NAD ϩ and a decrease in SIRT1 activity (8) resulting in cell senescence.

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supporting

confidence: 59%

“…At physiological MgATP concentrations (6), 80% of human NAMPT is phosphorylated, but none of the reported NAMPT crystal structures (11,15,16) have described the phosphorylated enzyme or characterized the ATP/ADP binding site. The NAMPT inhibitor, FK866 (10) has validated the enzyme as a target for the development of new anticancer agents.…”

mentioning

confidence: 99%

A phosphoenzyme mimic, overlapping catalytic sites and reaction coordinate motion for human NAMPT

Burgos

Almo

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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“…Accumulating evidence suggests that visfatin exerts important dual effects as an intracellular cell cycle regulatory protein (iNampt), in addition to secreted cytokine (eNampt), capable of modulating innate immunity and inflammatory responses across various cell types. From an intracellular standpoint, visfatin is a dimeric type II phosphoribosyltransferase that serves a critical role as the rate-limiting step in the biosynthesis of NAD from nicotinomide and regulates the activity of NAD-dependent deacetylase Sirt1 in mammalian cells (30). On the other hand, visfatin appears to play an important role as a cytokine, secreted extracellularly in response to inflammatory stimuli such as lipopolysaccharide, TNF-␣, IL-1␤, and IL-6, capable of modulating the innate immune response in states of systemic inflammation and sepsis (6,15).…”

Section: Discussionmentioning

confidence: 99%

Visfatin activates eNOS via Akt and MAP kinases and improves endothelial cell function and angiogenesis in vitro and in vivo: translational implications for atherosclerosis

Lovren¹,

Pan²,

Shukla³

et al. 2009

American Journal of Physiology-Endocrinology and Metabolism

102

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-Improving endothelial nitric oxide synthase (eNOS) bioactivity and endothelial function is important to limit native, vein graft, and transplant atherosclerosis. Visfatin, a NAD biosynthetic enzyme, regulates the activity of the cellular survival factor, Sirt1. We hypothesized that visfatin may improve eNOS expression, endothelial function, and postnatal angiogenesis. In human umbilical vein (HUVEC) and coronary artery endothelial cells, we evaluated the effects of recombinant human visfatin on eNOS protein and transcript expression and mRNA stability, in the presence and absence of visfatin RNA silencing. We also assessed visfatin-induced protein kinase B (Akt) activation and its association with src-tyrosine kinases, phosphorylation of Ser 1177 within eNOS in the presence and absence of phosphatidylinositol 3-kinase (PI 3-kinase) inhibition with LY-294002, and evaluated the contributory role of extracellular signal-regulated kinase 1/2. Finally, we determined the impact of visfatin on HUVEC migration, proliferation, inflammation-induced permeability, and in vivo angiogenesis. Visfatin (100 ng/ml) upregulated and stabilized eNOS mRNA and increased the production of nitric oxide and cGMP. Visfatin-treated HUVEC demonstrated greater proliferation, migration, and capillary-like tube formation but less tumor necrosis factor-␣-induced permeability; these effects were decreased in visfatin gene-silenced cells. Visfatin increased total Akt and Ser 473 -phosphoAkt expression with concomitant rises in eNOS phosphorylation at Ser 1177 ; these effects were blocked by LY-2940002. Studies with PP2 showed that the nonreceptor tyrosine kinase, src, is an upstream stimulator of the PI 3-kinase-Akt pathway. Visfatin also activated mitogen-activated protein (MAP) kinase through PI 3-kinase, and mitogen/extracellular signal-regulated kinase inhibition attenuated visfatin-elicited Akt and eNOS phosphorylation. Visfatin-filled Matrigel implants showed an elevated number of infiltrating vessels, and visfatin treatment produced significant recovery of limb perfusion following hindlimb ischemia. These results indicate a novel effect of visfatin to stimulate eNOS expression and function in endothelial cells, via a common upstream, src-mediated signaling cascade, which leads to activation of Akt and MAP kinases. Visfatin represents a translational target to limit endothelial dysfunction, native, vein graft and transplant atherosclerosis, and improve postnatal angiogenesis. nitric oxide; mice; endothelium; atherosclerosis; visfatin; protein kinase B; phosphatidylinositol 3-kinase; mitogen-activated protein kinase; endothelial nitric oxide synthase

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“…It was also identified as cytosolic nicotinamide phosphoribosyltransferase (NAMPT), demonstrated by in vitro, in vivo, and structural studies [7][8][9]. This enzyme is involved in nicotinamide adenine dinucleotide (NAD) biosynthesis [8].…”

Section: Introductionmentioning

confidence: 99%

The circulating PBEF/NAMPT/visfatin level is associated with a beneficial blood lipid profile

Wang

Greevenbroek

Bouwman

et al. 2007

Pflugers Arch - Eur J Physiol

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Visfatin with the official gene name pre-B cell colony-enhancing factor 1 (PBEF) and the protein name nicotinamide phosphoribosyltransferase (NAMPT) is a recently discovered adipocyte-secreted protein that was shown by some to be associated with visceral fat and insulin resistance. To explore the link between PBEF/ NAMPT/visfatin and lipid metabolism, we analyzed the relation of its plasma level with several parameters of adiposity, insulin resistance and the circulating blood lipid profile in a group of general population (n=40) and a group of subjects who are genetically predisposed to insulin resistance and hyperlipidemia (n=35). In both groups and pooled cohort, PBEF/NAMPT/visfatin lacked association with whole body adiposity, but correlated positively with HDL-cholesterol and negatively with triglycerides. The data suggested a negative correlation of the PBEF level with visceral fat and insulin resistance. But this negative correlation completely disappeared after adjustment for lipid profile. We concluded that circulating PBEF/NAMPT/ visfatin level is an indicator of beneficial lipid profile in non-diabetic Caucasian subjects. The relation to lipid metabolism does not depend on visceral obesity and insulin resistance, but may be linked to its enzymatic function in NAD metabolism.

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Structure of Nampt/PBEF/visfatin, a mammalian NAD+ biosynthetic enzyme

Cited by 254 publications

References 16 publications

A phosphoenzyme mimic, overlapping catalytic sites and reaction coordinate motion for human NAMPT

A phosphoenzyme mimic, overlapping catalytic sites and reaction coordinate motion for human NAMPT

Visfatin activates eNOS via Akt and MAP kinases and improves endothelial cell function and angiogenesis in vitro and in vivo: translational implications for atherosclerosis

The circulating PBEF/NAMPT/visfatin level is associated with a beneficial blood lipid profile

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