Paraoxonases (PONs) are a family of enzymes with a wide range of activities, including drug metabolism, deoxidization of lipids, and detoxification of organophosphates. The
mec-6 gene in Caenorhabditis elegans encodes a paraoxonase-like protein that is part of the MEC-4 channel complex that transduces gentle touch in the touch receptor neurons (TRNs) and is required for neurodegeneration caused by gain-of-function mutations in DEG/ENaC genes (e.g.,
mec-4 and
deg-1). C. elegans has four other PONs-like genes:
k11e4.3,
e01a2.7,
k05f6.11 and
e01a2.10 whose products remain uncharacterized. We found that K11E4.3::YFP translational fusion is expressed in the TRNs and a few other neurons. In the processes of the TRNs, K11E4.3::YFP is distributed as puncta that co-localize with MEC-6 puncta. K11E4.3 is required for touch sensitivity in sensitized backgrounds, specifically in
mec-6ts animals at the permissive temperature or
mec-6 hypomorphic alleles that do not, on their own, produce touch insensitivity. These data suggest that the touch transduction complex may have more than one of these proteins. We are currently examining the expressing of all the C. elegans PON-like genes. Two,
k05f6.11 and
e01a2.10, are expressed in the hypodermis.