Probable gustatory receptor which mediates acceptance or avoidance behavior, depending on its substrates (By similarity). Atypical expression suggests also nongustatory roles in the nervous system and tissues involved in proprioception, hygroreception, and other sensory modalities. It is also possible that it has chemosensory roles in the detection of internal ligands. In addition to expression in a large number of taste neurons, Gr28a is also expressed in a few nonchemosensory neurons, including the campaniform sensilla of the wing, leg stretch receptors, and multiple dendritic (MD) neurons in the abdomen. In larvea, is expressed in neurons of the terminal external chemosensory organ, the dorsal external chemosensory organ, as well as in the ventral and posterior pharyngeal sense organ. Belongs to the insect chemoreceptor superfamily. Gustatory receptor (GR) family. Gr2a subfamily.