The EGL-3 proprotein convertase regulates mechanosensory responses of Caenorhabditis elegans.

Neuroactive peptides are packaged as proproteins into dense core vesicles or secretory granules, where they are cleaved at dibasic residues by copackaged proprotein convertases. We show here that the Caenorhabditis elegans egl-3 gene encodes a protein that is 57% identical to mouse proprotein convertase type 2 (PC2), and we provide evidence that this convertase regulates mechanosensory responses. Nose touch sensitivity (mediated by ASH sensory neurons) is defective in mutants lacking GLR-1 glutamate receptors (GluRs); however, mutations eliminating the egl-3 PC2 restored nose touch sensitivity to glr-1 GluR mutants. By contrast, body touch sensitivity (mediated by the touch cells) is greatly diminished in egl-3 PC2 mutants. Taken together, these results suggest that egl-3 PC2-processed peptides normally regulate the responsiveness of C. elegans to mechanical stimuli.