SLC29A1: Equilibrative Nucleoside Transporter 1 (ENT1) Gene
A comprehensive biomedical overview of SLC29A1, encoding the equilibrative nucleoside transporter ENT1, with roles in nucleoside salvage, adenosine regulation, and pharmacogenomics.
Gene Information Card
| Symbol | SLC29A1 |
|---|---|
| Full Name | Solute Carrier Family 29 Member 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 6p21.1 |
| NCBI Gene ID | 2030 ncbi.nlm.nih.gov/gene/2030 |
| Ensembl ID | ENSG00000112759 |
| UniProt ID | Q99808 |
| OMIM ID | 602193 |
| HGNC ID | 10996 |
| Aliases | ENT1, equilibrative nitrobenzylthioinosine-sensitive nucleoside transporter |
Description
SLC29A1 encodes the equilibrative nucleoside transporter 1 (ENT1), a plasma membrane protein that mediates the bidirectional, sodium-independent transport of nucleosides (e.g., adenosine, uridine, cytidine) and nucleoside analog drugs (e.g., gemcitabine, cytarabine). ENT1 is widely expressed and plays critical roles in nucleoside salvage pathways, adenosine signaling, and cellular uptake of antiviral and anticancer nucleoside analogs. Genetic variants in SLC29A1 can affect drug efficacy and toxicity, and have been linked to a rare genetic disorder (H syndrome) and cancer susceptibility.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| H syndrome | Biallelic loss-of-function mutations in SLC29A1 cause defective nucleoside transport, leading to systemic inflammation, fibrosis, and hyperpigmentation. | OMIM #602193; ClinVar |
| Pancreatic cancer | Reduced ENT1 expression correlates with poor response to gemcitabine chemotherapy, as ENT1 is the primary transporter for drug uptake. | PMID: 25024190; COSMIC |
| Colorectal cancer | SLC29A1 promoter methylation and downregulation are associated with resistance to nucleoside analogs. | PMID: 23444215 |
| Coronary artery disease | Polymorphisms in SLC29A1 may affect adenosine-mediated vasodilation and cardiovascular risk. | PMID: 19805644 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Whole blood | 12.4 | Medium |
| Liver | 8.2 | Low |
| Kidney | 7.5 | Low |
| Lung | 6.1 | Low |
| Brain | 5.3 | Low |
| Skeletal muscle | 4.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 15.2 | High expression; used in transport assays |
| A549 | 10.1 | Moderate; lung cancer line |
| MCF7 | 8.7 | Moderate; breast cancer line |
| HepG2 | 6.3 | Low; liver line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1160G>A (p.Arg387His) | Missense | 0.01% (gnomAD) | Reduced transport activity; associated with H syndrome |
| c.1180C>T (p.Arg394Trp) | Missense | 0.005% | Loss of function; H syndrome |
| c.1400A>G (p.Tyr467Cys) | Missense | 0.002% | Impaired nucleoside uptake |
| c.−134C>T (promoter) | Regulatory | 5% (population) | Reduced ENT1 expression; affects gemcitabine response |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Arg387His) impair nucleoside transport, leading to H syndrome.
Gain of Function (GOF)
No clear gain-of-function mutations reported; overexpression in some cancers may increase drug uptake.
Dominant Negative (DN)
Not documented; SLC29A1 functions as a monomer, so dominant-negative effects are unlikely.
View complete mutation data：
Gene Ontology (GO)
| • nucleoside transmembrane transporter activity | • equilibrative nucleoside transporter activity |
| • adenosine transport | • uridine transport |
| • plasma membrane | • integral component of plasma membrane |
Pathways
• Nucleoside salvage pathway
• Adenosine signaling (via ENT1-mediated uptake)
• Pyrimidine metabolism
• Drug transport (gemcitabine
• cytarabine)
Protein Summary
ENT1 is a 456-amino acid glycoprotein with 11 transmembrane domains. It functions as a facilitative transporter, moving nucleosides down their concentration gradient. It is sensitive to inhibition by nitrobenzylthioinosine (NBMPR). ENT1 is ubiquitously expressed, with highest levels in erythrocytes and certain epithelia. It regulates extracellular adenosine levels, influencing inflammation, neurotransmission, and cardiovascular function. In cancer, ENT1 expression is a predictive biomarker for gemcitabine efficacy.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SLC29A1 Knockout HEK293 Cell Line | EDJ-KQ4531 | Human | 2030 | Details Get a Quote |
| SLC29A1 Knockout A-549 Cell Line | EDJ-KQ27147 | Human | 2030 | Details Get a Quote |
| SLC29A1 Knockout HCT 116 Cell Line | EDC08625 | Human | 2030 | Details Get a Quote |
| SLC29A1 Knockout HeLa Cell Line | EDJ-KQ27149 | Human | 2030 | Details Get a Quote |
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