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MGP004575

UniProt Annotations

Entry Information
Gene Namenicotinamide nucleotide adenylyltransferase 2
Protein EntryNMNA2_HUMAN
UniProt IDQ9BZQ4
SpeciesHuman
Comments
Comment typeDescription
Alternative ProductsEvent=Alternative splicing; Named isoforms=2; Name=1; IsoId=Q9BZQ4-1; Sequence=Displayed; Name=2; IsoId=Q9BZQ4-2; Sequence=VSP_015571; Note=No experimental confirmation available.;
Biophysicochemical PropertiesKinetic parameters: KM=32 uM for NMN {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; KM=70 uM for NAD(+) {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; KM=204 uM for ATP {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; KM=1119 uM for PPi {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; KM=14.5 uM for NaMN {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; KM=304 uM for NMNH {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; Vmax=1.1 umol/min/mg enzyme for NAD synthesis {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; Vmax=3 umol/min/mg enzyme for pyrophosphorolytic NAD(+) cleavage {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; Vmax=7 umol/min/mg enzyme for pyrophosphorolytic NADH cleavage {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}; Note=KM is >100 uM for triazofurin monophosphate.; pH dependence: Optimum pH is 6.0-9.0. {ECO:0000269|PubMed:12359228, ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747};
Catalytic ActivityATP + beta-nicotinate-D-ribonucleotide = diphosphate + deamido-NAD(+).
Catalytic ActivityATP + nicotinamide ribonucleotide = diphosphate + NAD(+).
CofactorName=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000269|PubMed:12359228, ECO:0000269|PubMed:14516279, ECO:0000269|PubMed:17402747}; Note=Divalent metal cations. Mg(2+) confers the highest activity. {ECO:0000269|PubMed:12359228, ECO:0000269|PubMed:14516279, ECO:0000269|PubMed:17402747};
Enzyme RegulationInhibited by P1-(adenosine-5')-P3- (nicotinamide-riboside-5')-triphosphate (Np3AD) and P1-(adenosine- 5')-P4-(nicotinamide-riboside-5')-tetraphosphate (Np4AD). {ECO:0000269|PubMed:17402747}.
FunctionCatalyzes the formation of NAD(+) from nicotinamide mononucleotide (NMN) and ATP. Can also use the deamidated form; nicotinic acid mononucleotide (NaMN) as substrate but with a lower efficiency. Cannot use triazofurin monophosphate (TrMP) as substrate. Also catalyzes the reverse reaction, i.e. the pyrophosphorolytic cleavage of NAD(+). For the pyrophosphorolytic activity prefers NAD(+), NADH and NAAD as substrates and degrades nicotinic acid adenine dinucleotide phosphate (NHD) less effectively. Fails to cleave phosphorylated dinucleotides NADP(+), NADPH and NAADP(+). {ECO:0000269|PubMed:16118205, ECO:0000269|PubMed:17402747}.
PathwayCofactor biosynthesis; NAD(+) biosynthesis; NAD(+) from nicotinamide D-ribonucleotide: step 1/1.
Sequence CautionSequence=BAA32324.1; Type=Erroneous initiation; Evidence={ECO:0000305};
SimilarityBelongs to the eukaryotic NMN adenylyltransferase family. {ECO:0000305}.
Subcellular LocationCytoplasm {ECO:0000269|PubMed:16118205}. Golgi apparatus {ECO:0000269|PubMed:16118205}.
SubunitMonomer. {ECO:0000269|PubMed:12359228}.
Tissue SpecificityHighly expressed in brain, in particular in cerebrum, cerebellum, occipital lobe, frontal lobe, temporal lobe and putamen. Also found in the heart, skeletal muscle, pancreas and islets of Langerhans. {ECO:0000269|PubMed:12359228, ECO:0000269|PubMed:14516279, ECO:0000269|PubMed:16118205}.
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