NAPRT (Nicotinate Phosphoribosyltransferase)
Key enzyme in NAD+ salvage synthesis from nicotinic acid
Gene Information Card
| Symbol | NAPRT |
|---|---|
| Full Name | Nicotinate phosphoribosyltransferase |
| Gene Type | protein-coding |
| Chromosomal Location | 8q24.3 |
| NCBI Gene ID | 93100 ncbi.nlm.nih.gov/gene/93100 |
| Ensembl ID | ENSG00000147869 |
| UniProt ID | Q6XQN6 |
| OMIM ID | 610981 |
| HGNC ID | 30450 |
| Aliases | NAPRT1, NAPRTase, FLJ10891 |
Description
NAPRT encodes nicotinate phosphoribosyltransferase, a key enzyme in the Preiss-Handler pathway that converts nicotinic acid (niacin) to nicotinic acid mononucleotide (NaMN), a precursor for NAD+ synthesis. This enzyme is critical for NAD+ salvage from dietary niacin and is expressed in various tissues, with implications in cancer metabolism and neurodegenerative diseases.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Nicotinic acid deficiency | Impaired NAD+ salvage due to NAPRT loss-of-function | ClinVar |
| Cancer (various) | NAPRT overexpression supports NAD+ pool in tumors; potential therapeutic target | COSMIC, literature |
| Pellegra (niacin deficiency) | Indirect: reduced NAPRT activity exacerbates NAD+ depletion | OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | High |
| Kidney | 8.3 | Medium |
| Heart | 6.1 | Medium |
| Brain | 4.2 | Low |
| Skeletal muscle | 3.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 10.2 | Cervical cancer cell line |
| HepG2 | 14.7 | Hepatocellular carcinoma |
| A549 | 7.5 | Lung adenocarcinoma |
| MCF7 | 5.9 | Breast cancer |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon, likely loss-of-function |
| c.347C>T (p.Thr116Ile) | Missense | <0.01% | Unknown functional impact |
| c.769G>A (p.Gly257Arg) | Missense | <0.01% | Potential loss-of-function |
Mutation functional classification
Loss of Function (LOF)
Rare missense and start-loss variants reduce or abolish NAPRT enzymatic activity, impairing NAD+ salvage.
Gain of Function (GOF)
Not reported in NAPRT.
Dominant Negative (DN)
Not reported in NAPRT.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Nicotinate and nicotinamide metabolism (KEGG: hsa00760)
• NAD+ salvage pathway (Preiss-Handler pathway)
Protein Summary
Nicotinate phosphoribosyltransferase (NAPRT) is a 56 kDa cytoplasmic enzyme that catalyzes the conversion of nicotinic acid and 5-phosphoribosyl-1-pyrophosphate (PRPP) to nicotinic acid mononucleotide (NaMN) and pyrophosphate. It is the rate-limiting step in the Preiss-Handler pathway for NAD+ synthesis from dietary niacin. NAPRT is highly expressed in liver and kidney, and its upregulation in certain cancers suggests a role in supporting NAD+ demands for tumor growth.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| NAPRT Knockout HEK293 Cell Line | EDJ-KQ11164 | Human | 93100 | Details Get a Quote |
| NAPRT Knockout A-549 Cell Line | EDJ-KQ39179 | Human | 93100 | Details Get a Quote |
| NAPRT Knockout HCT 116 Cell Line | EDJ-KQ39180 | Human | 93100 | Details Get a Quote |
| NAPRT Knockout HeLa Cell Line | EDJ-KQ39181 | Human | 93100 | Details Get a Quote |
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