Thioredoxin reductase 1, cytoplasmic

Thioredoxin reductase 1 (TXNRD1) is a cytoplasmic selenoprotein that catalyzes the reduction of disulfide bonds in thioredoxin, regulating cellular redox homeostasis and supporting protein folding and cell growth (UniProt: Q16881). The enzyme contains a critical selenocysteine residue at its C-terminal active site and also exhibits reductase activity toward hydrogen peroxide. Beyond redox regulation, TXNRD1 promotes cytoskeletal reorganization through actin and tubulin polymerization and enhances transcriptional activity of estrogen receptors.

TXNRD1 is broadly involved in maintaining cellular redox balance and has roles in cell differentiation, proliferation, and death signaling. No disease associations are listed in the primary UniProt record.

In Alzheimer's disease, TXNRD1 shows increased expression in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The protein was upregulated with a mean log2 fold-change of 0.75 across two subcellular fractions in a TMT-labeled quantitative proteomics study of four cellular compartments. This upregulation may reflect adaptive oxidative stress responses in AD brain pathology.