To determine the spatial effect on expression of releasing
pmk-2 from regulation by the miR-58/80-82 family, we engineered a new pmk operon translational reporter, qdEx102, which carries mutations in the second and third miR-58/80-82 seed match sites in the 3'UTR of
pmk-2. Expression of PMK-1 was unchanged, whereas expression of PMK-2 was detected in many additional cell types including the intestine, body wall muscle, pharyngeal muscle, hypodermis, and vulva. Expression of PMK-2 in the distal tip cell and spermatheca, which was faint and dif- fuse with miR-58/80-82 regulation intact, was markedly elevated. Similar misexpression of
pmk-2 was observed when we crossed qdEx101 (pmk operon reporter with miR-58/80-82 seed match sites intact) into the
mir-80;
mir-58;
mir-81-82 mutant. These data suggest that the miR-58/80-82 family of microRNAs restricts expression of PMK-2
p38 MAPK through the post-transcriptional destabilization of
pmk-2 mRNA in non-neuronal tissues.