DHS-21, a dicarbonyl/l-xylulose reductase (DCXR) ortholog, regulates longevity and reproduction in Caenorhabditis elegans

Dicarbonyl/ l -xylulose reductase (DCXR) converts l -xylulose into xylitol, and reduces various α-dicarbonyl compounds, thus performing a dual role in carbohydrate metabolism and detoxification. In this study, we identified DHS-21 as the only DCXR ortholog in Caenorhabditis elegans . The dhs-21 gene is expressed in various tissues including the intestine, gonadal sheath cells, uterine seam (utse) cells, the spermathecal-uterus (sp-ut) valve and on the plasma membrane of spermatids. Recombinant DHS-21 was shown to convert l -xylulose to xylitol using NADPH as a cofactor. Dhs -21 null mutants of C. elegans show defects in longevity, reproduction and egg-laying. Knock-down of daf-16 and elt-2 transcription factors affected dhs-21 expression. These results suggest that DHS-21 is a bona fide DCXR of C. elegans , essential for normal life span and reproduction.