Probable gustatory receptor which mediates acceptance or avoidance behavior, depending on its substrates (By similarity). Seems to be involved in the sensing of bitter taste since it is expressed in neurons that mediate sensitivity to bitter compounds. Expressed in taste bristles in the foreleg and labial palps. In larvae, is expressed in neurons of the dorsal and posterior pharyngeal sense organs. Expressed in taste neurons that mediate sensitivity to bitter compounds. Belongs to the insect chemoreceptor superfamily. Gustatory receptor (GR) family. Gr22e subfamily.