Nudix Type Motif

NUDT9 is a member of a superfamily of Nudix hydrolases. NUDT9 functions as a highly specific adenosine diphosphate ribose pyrophosphatase which hydrolyzes ADP ribose to AMP and ribose 5'-phosphate. In addition, NUDT9 may be involved in the regulation of the menstrual cycle and may be related to the proliferation of glandular cells in the human endometrium.

NUDT5 is part of the nudix hydrolase family which remove toxic nucleotide derivatives from the cell. NUDT5 hydrolyzes ADP-ribose and ADP-mannose in the presence of magnesium, and in addition hydrolyzes nucleotide sugars with decreasing activity such as ADP-glucose and diadenosine diphosphate. As a nudix hydrolase, NUDT5 holds a central nudix motif and functions to eliminate toxic nucleotide metabolites from the cell while maintaining the levels of signaling nucleotides.
NUDT5 is broadly expressed but is most abundant in liver as a homodimer.

Nudix Type Motif 4 (NUDT4) regulates the turnover of diphosphoinositol polyphosphates. The turnover of these high-energy diphosphoinositol polyphosphates exemplifies a molecular switching activity with significant regulatory consequences. Molecular switching by diphosphoinositol polyphosphates may be a factor in regulating intracellular trafficking.

NUDT3 is a 172 amino acid cytoplasmic protein which is a member of the nudix hydrolase family and DIPP subfamily. NUDT3 functions as a negative regulator of the ERK 1/2 pathway and hydrolyzes 5-phosphoribose 1-diphosphate. NUDT3 is a monomer which binds magnesium as a cofactor. In addition, NUDT3 is widely expressed but can be found at highest levels in the liver, pancreas, brain and heart.

NUDT21 belongs to the Nudix hydrolase family of pyrophosphatases. NUDT21 localizes to the paraspeckles and forms a heterodimer with CPSF6 or CPSF7 to comprise the CFIm (mammalian cleavage factor I) complex. NUDT21 being the smaller subunit of the complex, is present in all heterodimer combinations. NUDT21 has a vital role in pre-mRNA 3' cleavage and polyadenylation processing.

NUDT2 belongs to the MutT family of nucleotide pyrophosphatases, a subset of the larger NUDIX hydrolase family. NUDT2 conserves homeostasis by using water to cleave the metabolite NUDT symmetrically back into its original ATP and AMP molecules. In addition, NUDT2 is active towards other adenosine and diadenosine polyphosphates with four or more phosphate groups, however, not towards diadenosine triphosphate. NUDT2 has a role in heat shock and metabolic stress by regulating intracellular dinucleoside polyphosphate concentrations.

Syndesmos (NUDT16L1) is a cytoplasmic protein which interacts specifically with the cytoplasmic domain of syndecan-4, and co-localizes with syndecan-4 in focal contacts. NUDT16L1 interacts with the focal adhesion adaptor protein paxillin. The binding of NUDT16L1 to paxillin is direct, and these interactions are triggered by the activation of protein kinase C.

NUDT16 is nuclear nucleoside diphosphatase proteins restricted in foci in the nucleolus and nucleoplasm. NUDT16 is a RNA-decapping enzyme. It binds specifically to U8 snoRNA and can remove m7G and m227G caps from RNAs, rendering them substrates for 5’-3’ exonucleases for degradation in vivo.

Uridine diphosphate glucose pyrophosphatase (NUDT14), is a part of the nudix hydrolase family. NUDT14 is a cytoplasmic protein which contains one nudix hydrolase domain and acts as the sugar donor in numerous glycosylation reactions, including those involved in the production of glycogen. NUDT14 hydrolyzes ADP-ribose into ribose 5-phosphate and AMP, and UDP-glucose to glucose 1-phosphate and UMP. NUDT14 is a homodimer which binds magnesium as a cofactor and is encoded by a gene located on human chromosome 14.

NUDT10 belongs to the Nudix hydrolase family of pyrophosphatases. Nudix hydrolases contain a characteristic Nudix domain and are responsible for catalyzing the hydrolysis of nucleoside diphosphate derivatives. NUDT10 functions as a manganese-dependent polyphosphate phosphohydrolase with an optimum pH of 8.5. NUDT10 protein specifically metabolizes diadendosine-polyphosphates and, to a lesser extent, diphosphoinositol polyphosphates.

NUDT1 is an enzyme that hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP, 8-oxo-dATP, 2-hydroxy-dATP, and 2-hydroxy rATP, to monophosphates, thereby preventing misincorporation of 8-oxo-dGTP into DNA thus preventing A:T to C:G transversions. NUDT1 is found mostly in the cytoplasm, with some in the mitochondria, suggesting that it is involved in the sanitization of nucleotide pools both for nuclear and mitochondrial genomes. Moreover, NUDT1 is expressed at much higher levels in proliferating cells than in resting cells. Misincorporation of oxidized nucleoside triphosphates into DNA/RNA during replication and transcription can cause mutations which may result in carcinogenesis or neurodegeneration.