scholarly journals The human silent information regulator (Sir)2 homologue hSIRT3 is a mitochondrial nicotinamide adenine dinucleotide–dependent deacetylase

2002 ◽  
Vol 158 (4) ◽  
pp. 647-657 ◽  
Author(s):  
Björn Schwer ◽  
Brian J. North ◽  
Roy A. Frye ◽  
Melanie Ott ◽  
Eric Verdin
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Mammalian Cells ◽  
Latent Class ◽  
Trichostatin A ◽  
Hydrolysis Product ◽  
Nicotinamide Adenine ◽  
Mitochondrial Matrix ◽  
Class Iii ◽  
Α Helix

The yeast silent information regulator (Sir)2 protein links cellular metabolism and transcriptional silencing through its nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase activity. We report that mitochondria from mammalian cells contain intrinsic NAD-dependent deacetylase activity. This activity is inhibited by the NAD hydrolysis product nicotinamide, but not by trichostatin A, consistent with a class III deacetylase. We identify this deacetylase as the nuclear-encoded human Sir2 homologue hSIRT3, and show that hSIRT3 is located within the mitochondrial matrix. Mitochondrial import of hSIRT3 is dependent on an NH2-terminal amphipathic α-helix rich in basic residues. hSIRT3 is proteolytically processed in the mitochondrial matrix to a 28-kD product. This processing can be reconstituted in vitro with recombinant mitochondrial matrix processing peptidase (MPP) and is inhibited by mutation of arginines 99 and 100. The unprocessed form of hSIRT3 is enzymatically inactive and becomes fully activated in vitro after cleavage by MPP. These observations demonstrate the existence of a latent class III deacetylase that becomes catalytically activated upon import into the human mitochondria.

scholarly journals Mammalian Nudix proteins cleave nucleotide metabolite caps on RNAs

2020 ◽  
Vol 48 (12) ◽  
pp. 6788-6798 ◽  
Author(s):  
Sunny Sharma ◽  
Ewa Grudzien-Nogalska ◽  
Keith Hamilton ◽  
Xinfu Jiao ◽  
Jun Yang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nicotinamide Adenine Dinucleotide ◽  
Mammalian Cells ◽  
Flavin Adenine Dinucleotide ◽  
Nicotinamide Adenine ◽  
Nudix Hydrolase ◽  
Decapping Enzymes ◽  
Hydrolysis Of ◽  
In Cells

Abstract We recently reported the presence of nicotinamide adenine dinucleotide (NAD)-capped RNAs in mammalian cells and a role for DXO and the Nudix hydrolase Nudt12 in decapping NAD-capped RNAs (deNADding) in cells. Analysis of 5′caps has revealed that in addition to NAD, mammalian RNAs also contain other metabolite caps including flavin adenine dinucleotide (FAD) and dephosphoCoA (dpCoA). In the present study we systematically screened all mammalian Nudix proteins for their potential deNADing, FAD cap decapping (deFADding) and dpCoA cap decapping (deCoAping) activity. We demonstrate that Nudt16 is a novel deNADding enzyme in mammalian cells. Additionally, we identified seven Nudix proteins—Nudt2, Nudt7, Nudt8, Nudt12, Nudt15, Nudt16 and Nudt19, to possess deCoAping activity in vitro. Moreover, our screening revealed that both mammalian Nudt2 and Nudt16 hydrolyze FAD-capped RNAs in vitro with Nudt16 regulating levels of FAD-capped RNAs in cells. All decapping activities identified hydrolyze the metabolite cap substrate within the diphosphate linkage. Crystal structure of human Nudt16 in complex with FAD at 2.7 Å resolution provide molecular insights into the binding and metal-coordinated hydrolysis of FAD by Nudt16. In summary, our study identifies novel cellular deNADding and deFADding enzymes and establishes a foundation for the selective functionality of the Nudix decapping enzymes on non-canonical metabolite caps.

NAD(P)H oxidase–dependent platelet superoxide anion release increases platelet recruitment

Blood ◽  
2002 ◽  
Vol 100 (3) ◽  
pp. 917-924 ◽  
Author(s):  
Florian Krötz ◽  
Hae Young Sohn ◽  
Torsten Gloe ◽  
Stefan Zahler ◽  
Tobias Riexinger ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Thrombus Formation ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Human Platelets ◽  
Nicotinamide Adenine ◽  
Irreversible Aggregation ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Specific Peptide

Abstract Platelets, although not phagocytotic, have been suggested to release O2−. Since O2−-producing reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) oxidases can be specifically activated by certain agonists and are found in several nonphagocytotic tissues, we investigated whether such an enzyme is the source of platelet-derived O2−. We further studied which agonists cause platelet O2−release and whether platelet-derived O2− influences thrombus formation in vitro. Collagen, but not adenosine 5′-diphosphate (ADP) or thrombin, increased O2− formation in washed human platelets. This was a reduced nicotinamide adenine dinucleotide (NADH)–dependent process, as shown in platelet lysates. Consistent with a role of a platelet, NAD(P)H oxidase expression of its subunits p47phox and p67phoxand inhibition of platelet O2− formation by diphenylene-iodoniumchloride (DPI) and by the specific peptide-antagonist gp91ds-tat were observed. Whereas platelet-derived O2− did not influence initial aggregation, platelet recruitment to a preformed thrombus following collagen stimulation was significantly attenuated by superoxide dismutase (SOD) or DPI. It was also inhibited when ADP released during aggregation was cleaved by the ectonucleotidase apyrase. ADP in supernatants of collagen-activated platelets was decreased in the presence of SOD, resulting in lower ADP concentrations available for recruitment of further platelets. Exogenous O2−increased ADP- concentrations in supernatants of collagen-stimulated platelets and induced irreversible aggregation when platelets were stimulated with otherwise subthreshold concentrations of ADP. These results strongly suggest that collagen activation induces NAD(P)H oxidase–dependent O2− release in platelets, which in turn enhances availability of released ADP, resulting in increased platelet recruitment.

scholarly journals Minireview: NAD+, a Circadian Metabolite with an Epigenetic Twist

Endocrinology ◽  
2012 ◽  
Vol 153 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Paolo Sassone-Corsi
Keyword(s):  
Circadian Clock ◽  
Nicotinamide Adenine Dinucleotide ◽  
Mammalian Cells ◽  
Feedback Loop ◽  
Large Fraction ◽  
Sirtuin 1 ◽  
Nicotinamide Adenine ◽  
Dynamic Changes ◽  
Metabolic Functions ◽  
Transcriptional Feedback

Abstract A wide variety of endocrine, physiological, and metabolic functions follow daily oscillations. Most of these regulations are controlled at the level of gene expression by the circadian clock and, a remarkably coordinated transcription-translation machinery that exerts its function in virtually all mammalian cells. A large fraction of the genome is under control of the circadian clock, a regulation that is achieved through dynamic changes in chromatin states. Recent findings have demonstrated intimate connections between the circadian clock and epigenetic control. The case of nicotinamide adenine dinucleotide, which modulates the circadian activity of the deacetylase sirtuin 1, constitutes a paradigmatic example of the link between cyclic cellular metabolism and chromatin remodeling. Indeed, the clock transcriptional feedback loop is interlocked with the enzymatic loop of the nicotinamide adenine dinucleotide salvage pathway.

scholarly journals IL8 Drives an Elaborate Signal Transduction Process for CD38 to Produce NAADP from NAAD and NADP+ in Endolysosomes to Effect Cell Migration

2020 ◽  
Author(s):  
Tae-Sik Nam ◽  
Dae-Ryoung Park ◽  
So-Young Rah ◽  
Tae-Gyu Woo ◽  
Hun Taeg Chung ◽  
...  
Keyword(s):  
Cell Migration ◽  
Nicotinic Acid ◽  
Nicotinamide Adenine Dinucleotide ◽  
Connexin 43 ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Type Ii ◽  
Lymphokine Activated Killer Cells ◽  
Base Exchange

AbstractNicotinic acid adenine dinucleotide phosphate (NAADP) is an obligate driver of calcium signaling whose formation from other metabolites of nicotinamide adenine dinucleotide (NAD+) has remained elusive. In vitro, CD38-mediated NAADP synthesis requires an acidic pH and a nonphysiological concentration of nicotinic acid (NA). We discovered that the type II membrane form of CD38 catalyzes synthesis of NAADP by exchanging the nicotinamide moiety of nicotinamide adenine dinucleotide phosphate (NADP+) for the NA group of nicotinic acid adenine dinucleotide (NAAD) inside endolysosomes of interleukin 8 (IL8)-treated lymphokine-activated killer cells. Upon IL8 stimulation, cytosolic NADP+ is transported to acidified endolysosomes via connexin 43 via cAMP-EPAC-RAP1-PP2A signaling. Luminal CD38 then performs a base exchange reaction with the donor NA group deriving from NAAD, produced by newly described endolysosomal activities of NA phosphoribosyltransferase and NMN adenyltransferase 3. Thus, the membrane organization of endolysosomal CD38, a signal-mediated transport system for NADP+ and luminal NAD+ biosynthetic enzymes integrate signals from a chemokine and cAMP to specify the spatiotemporal mobilization of calcium to drive cell migration.

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