Exposure of cells to arsenicals activates multiple stress pathways resultin
g in the induction of specific genes whose identity and role in the adaptat
ion to arsenical-induced cellular stress are poorly understood. We report h
ere the identification of a novel gene encoding an arsenite-inducible, cyst
eine- and histidine-rich RNA-associated protein, AIRAP, that is conserved a
mong mammals, Drosophila and C elegans. Immunochemistry and cell fractionat
ion experiments indicate that, when induced, AIRAP is present in both the n
ucleus and the cytoplasm, and cross-linking experiments indicate that it as
sociates with RNA in vivo. The expression of a C elegans homologue of AIRAP
, aip-l, is also induced by exposure to arsenite, and expression of an aip-
1::gfp transgene is most pronounced in hypodermal cells. RNA-mediated inter
ference (RNAi) of aip-1 lowers the resistance of nematodes to arsenite yet
does not appear to affect viability under standard growth conditions. These
experiments suggest a role for AIRAP/AIP-1 in protecting cells from the to
xic effects of arsenite.