| TXNRD1 Protein |
|---|
| Protein Name | Thioredoxin Reductase 1 |
| Gene Symbol | [TXNRD1](/genes/txnrd1) |
| UniProt ID | [Q16881](https://www.uniprot.org/uniprot/Q16881) |
| PDB Structures | 2JLP, 3EAN, 4LSU |
| Molecular Weight | 54,713 Da |
| Subcellular Localization | Cytoplasm, Nucleus |
| Protein Family | Pyridine nucleotide-disulfide oxidoreductase family |
TXNRD1 Protein is a protein. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
Thioredoxin reductase 1 (TXNRD1) is a homodimeric flavoenzyme, with each subunit containing FAD, NADPH, and a redox-active disulfide. The protein consists of approximately 500 amino acids and has a modular structure:
- N-terminal domain: Contains the NADPH-binding site and the first redox-active disulfide
- C-terminal domain: Contains the second redox-active site with a selenocysteine (Sec) residue
- The Sec (UGA codon) is essential for catalytic activity
TXNRD1 uses NADPH as the electron donor to reduce thioredoxin (TXN), maintaining it in a reduced state. The enzyme contains a rare selenocysteine at position 496, making it one of few selenoproteins in mammals.
TXNRD1 is a key component of the thioredoxin system, essential for neuronal redox homeostasis:
- Thioredoxin reduction: Maintains thioredoxin in reduced state
- Antioxidant defense: Protects against oxidative stress
- DNA synthesis: Provides reducing equivalents for ribonucleotide reductase
- Transcription factor regulation: Modulates NF-kB, AP-1 activity through thioredoxin
- Apoptosis regulation: Controls caspase activity through thioredoxin
- Protein repair: Reduces oxidized protein thiols
In neurons, TXNRD1 is crucial for maintaining redox balance given high metabolic demand and exposure to reactive oxygen species.
TXNRD1 activity is altered in AD:
- TXNRD1 expression and activity reduced in AD brain
- Contributes to increased oxidative stress
- Thioredoxin system dysfunction exacerbates amyloid pathology
- Oxidized thioredoxin in AD brain
- Therapeutic restoration shows promise
TXNRD1 plays a protective role in PD:
- Protects dopaminergic neurons from oxidative damage
- TXNRD1 expression increased as compensatory response
- Interacts with parkin and PINK1 pathways
- TXNRD1 polymorphisms affect PD risk
In ALS:
- TXNRD1 activity reduced in motor neurons
- Mutant SOD1 interacts with thioredoxin system
- Oxidative stress from TXNRD1 dysfunction
- Therapeutic potential of TXNRD1 modulators
¶ Stroke and Ischemia
TXNRD1 is protective in cerebral ischemia:
- TXNRD1 expression upregulated in ischemic preconditioning
- Maintains neuronal survival through redox regulation
- Gene therapy approaches neuroprotective
- TXNRD1 dysfunction contributes to oxidative stress
- Thioredoxin system impaired in HD models
TXNRD1 modulators are being developed:
-
TXNRD1 inhibitors (for cancer):
- Auranofin (FDA-approved)
- Dansylcadaverine derivatives
- Sec-site targeting compounds
-
TXNRD1 activators (for neurodegeneration):
- Selenium supplementation
- Gene therapy approaches
- Thioredoxin mimetics
-
Combined approaches:
- TXNRD1 with thioredoxin
- Antioxidant combinations
- Thioredoxin system in Alzheimer's disease
- TXNRD1 neuroprotection in PD models
- Selenoproteins in neurodegeneration
- TXNRD1 in ALS pathogenesis
- Thioredoxin reductase as therapeutic target