Altered neuropeptide profile of Caenorhabditis elegans lacking the chaperone protein 7B2 as analyzed by mass spectrometry.

Cellular synthesis of naturally occurring, bioactive peptides requires the proprotein convertase PC2/EGL-3 for cleavage from the larger peptide precursors. A neuroendocrine chaperone 7B2 is needed for the proteolytical activation of proPC2, as extensively studied in mouse models. To determine the role of its orthologue in Caenorhabditis elegans, we analyzed wild-type and 7B2-null strains by HPLC and matrix-assisted laser desorption ionization time-of-flight mass spectrometry, which allowed the identification of a novel neuropeptide gene, flp-33. The presence and/or absence of some neuropeptides in 7B2-null animals strongly differs form the peptide profile in wild-type, suggesting a specific and determined action of 7B2 in C. elegans.