| Gene | SLC11A2 |
| UniProt | [P49281](https://www.uniprot.org/uniprot/P49281) |
| Molecular Weight | 62 kDa |
| Subcellular Localization | Plasma membrane, Endosomes, Lysosomes |
| PDB Structures | [6M1P](https://www.rcsb.org/structure/6M1P) (bacterial homolog) |
| Aliases | Nramp2, DCT1, SLC11A2 |
DMT1 (Divalent Metal Transporter 1), encoded by the SLC11A2 gene, is a proton-coupled metal ion transporter responsible for the uptake of dietary iron and endosomal iron release following transferrin receptor-mediated endocytosis. DMT1 is essential for systemic iron homeostasis and is critically involved in iron accumulation in neurodegenerative diseases, particularly Parkinson's disease where iron accumulates in the substantia nigra.[1]
DMT1 is a 561-amino acid transmembrane protein with 12 predicted transmembrane domains:[2]
Key structural features:
The +IRE isoforms are regulated by cellular iron status through IRP binding, while -IRE isoforms show constitutive expression. The 1A isoforms localize primarily to the plasma membrane, while 1B isoforms are found in endosomal/lysosomal compartments.[3]
DMT1 is the primary transporter for non-heme iron uptake:[4]
Dietary iron absorption: DMT1 in duodenal enterocytes transports ferrous iron (Fe²⁺) from the intestinal lumen into cells, coupled with proton co-transport
Endosomal iron transport: Following transferrin receptor internalization and endosomal acidification, DMT1 exports iron from endosomes to the cytosol
Transport mechanism:
Fe²⁺ (extracellular/endosomal) + H⁺ → Fe²⁺ (cytosol) + H⁺ (cytosol)
Substrate specificity: Also transports Mn²⁺, Co²⁺, Cu²⁺, Zn²⁺, and other divalent metals
Iron regulation: +IRE isoforms are stabilized by IRPs under low iron conditions, increasing expression
DMT1 is critically implicated in the characteristic iron accumulation in the substantia nigra of PD patients:[5]
Key findings:
Mechanism of iron accumulation:
α-Synuclein aggregates → DMT1 upregulation → Fe²⁺ influx ↑ →
Fenton chemistry → ROS ↑ → Dopaminergic neuron death
The Belgrade rat (DMT1 G185R mutation) is protected from Parkinsonian neurotoxins (MPTP, 6-OHDA), demonstrating DMT1's essential role in iron-mediated neurodegeneration.[7]
DMT1 contributes to iron dysregulation in AD:
Amyotrophic Lateral Sclerosis (ALS):
Friedreich's Ataxia:
| Strategy | Mechanism | Status |
|---|---|---|
| Small molecule inhibitors | Block iron transport | Preclinical |
| siRNA/shRNA | Reduce DMT1 expression | Research |
| Iron chelation | Reduce labile iron pool | Clinical trials |
| Metal ion competition | Mn²⁺ or Co²⁺ competition | Research |
Several compounds show DMT1 inhibitory activity:[8]
The most promising clinical approach combines DMT1 modulation with iron chelation:
| Interacting Partner | Function | Relevance |
|---|---|---|
| Transferrin Receptor | Endosomal iron uptake | Sequential transport pathway |
| Ferroportin | Iron export | Balance import/export |
| Hephaestin | Iron oxidation | Enterocyte iron handling |
| STEAP3 | Endosomal iron reduction | Provides Fe²⁺ substrate |
| IRP1/IRP2 | Post-transcriptional regulation | IRE binding |
Fleming et al., Microcytic anaemia mice have a mutation in Nramp2 (1997) — Nature Genetics. Discovery of DMT1 as the iron transporter mutated in microcytic anemia.
Salazar et al., DMT1 expression in substantia nigra in Parkinson's disease (2008) — Demonstrates DMT1 upregulation in PD substantia nigra.
Garrick et al., DMT1 in neurodegeneration (2012) — Comprehensive review of DMT1's role in neurodegenerative diseases.
Aguirre et al., Iron chelation and neuroprotection in Parkinson's disease (2021) — Reviews iron chelation strategies targeting DMT1-mediated iron uptake.
Cheli et al., Nutritional iron regulation and DMT1 (2023) — Updated review of DMT1 function and regulation.
Gunshin H, et al. Cloning and characterization of a mammalian proton-coupled metal-ion transporter. Nature. 1997. ↩︎
Shawki A, et al. Molecular characterization of DMT1. Biochimica et Biophysica Acta. 2012. ↩︎
Hubert N, Hentze MW. Previously uncharacterized isoforms of divalent metal transporter (DMT)-1: implications for regulation and cellular function. Proceedings of the National Academy of Sciences. 2002. ↩︎
Mims MP, Prchal JT. Divalent metal transporter 1. Hematology. 2005. ↩︎
Salazar J, et al. DMT1 expression in substantia nigra in Parkinson's disease. Journal of Neural Transmission. 2008. ↩︎
Jiang H, et al. DMT1 regulation in Parkinson's disease. Neurobiology of Disease. 2021. ↩︎
Shukla A, et al. Protection of the Belgrade rat against 6-OHDA toxicity. Neurobiology of Disease. 2022. ↩︎
Zhang S, et al. Inhibition of DMT1: A therapeutic strategy for Parkinson's disease. Neuropharmacology. 2023. ↩︎