NMNAT3
Description
The NMNAT3 (nicotinamide nucleotide adenylyltransferase 3) is a protein-coding gene located on chromosome 3.
NMNAT3 is an enzyme encoded by the NMNAT3 gene in humans. It is one of three isoforms of nicotinamide-nucleotide adenylyltransferase (NMNAT) found in humans. Like other NMNATs, NMNAT3 catalyzes the synthesis of NAD+. It is highly expressed in the liver, heart, skeletal muscle, and erythrocytes. NMNAT3 is localized in mitochondria or cytoplasm depending on the cell type. Knockdown of NMNAT3 gene expression in cell culture significantly reduces mitochondrial function. NMNAT3 is crucial for maintaining NAD levels in red blood cells. The catechin epigallocatechin gallate, found in tea, can activate NMNAT3 by over 40%. As of 2017, mutations in the NMNAT3 gene have not been linked to any known diseases.
NMNAT3 catalyzes the synthesis of NAD+ from nicotinamide mononucleotide (NMN) and ATP. It can also utilize nicotinic acid mononucleotide (NaMN) as a substrate with equal efficiency. Additionally, NMNAT3 can use triazofurin monophosphate (TrMP) as a substrate and GTP or ITP as nucleotide donors. It also catalyzes the reverse reaction, the pyrophosphorolytic cleavage of NAD+, using substrates such as NAD+, NADH, NaAD, nicotinic acid adenine dinucleotide phosphate (NHD), and nicotinamide guanine dinucleotide (NGD). Notably, NMNAT3 does not cleave phosphorylated dinucleotides like NADP+, NADPH, and NaADP+. NMNAT3 plays a protective role against axonal degeneration following injury.
NMNAT3 is also known as FKSG76, PNAT-3, PNAT3.
Associated Diseases
- substance abuse
- beta-thalassemia-X-linked thrombocytopenia syndrome
- dehydrated hereditary stomatocytosis
- hereditary persistence of fetal hemoglobin-sickle cell disease syndrome
- hereditary elliptocytosis
- severe congenital hypochromic anemia with ringed sideroblasts
- hemoglobin D disease
- primary familial polycythemia due to EPO receptor mutation
- Rh deficiency syndrome
- X-linked sideroblastic anemia 1
- dominant beta-thalassemia
- hemoglobin E disease
- gamma-glutamylcysteine synthetase deficiency
- alpha-thalassemia-myelodysplastic syndrome
- hemoglobin H disease
- cryohydrocytosis
