Thioredoxin is related to life span regulation and oxidative stress response in Caenorhabditis elegans

Thioredoxin, an oxidoreductase, is a multifunction protein. The thioredoxin system is composed of NADPH, thioredoxin reductase and thioredoxin. This enzyme is highly conserved from bacteria to humans. We have characterized TRX‐1, a thioredoxin homolog in C. elegans, which has about 36% identity in amino acid sequence with human thioredoxin. By gfp reporter system, trx‐1 has been shown to be restrictedly expressed in ASI and ASJ neurons and in intestine. Immunostaining confirmed the intestinal expression. Full‐length cDNA of trx‐1 has been isolated by cDNA library PCR and subsequently cloned and sequenced. We have shown that the encoded protein functions as a reductase in the insulin reducing assay. Moreover, we have isolated a deletion mutant by PCR‐based TMP‐UV mutagenesis method. Mutant animals have reduced life span and are sensitive to oxidative stress. Reintroduction of trx‐1 into mutant worms fully restored the wild‐type phenotype. Our results suggest that trx‐1 has important functions in life span regulation and oxidative stress response in C. elegans.