G-protein coupled receptor for PDF neuropeptides (PubMed:18390545). Plays a role in responses to environmental signals, including chemicals and touch, and in modulating locomotory behaviors (PubMed:30024377, PubMed:18390545, PubMed:14551910, PubMed:22579613, PubMed:23143519, PubMed:23972393, PubMed:26113231). Capable of transducing signals via an adenylate cyclase acy-1 cAMP-dependent pathway (PubMed:23972393, PubMed:30024377). Required to regulate the sex-specific expression of TGFbeta-like daf-7 in the ASJ chemosensory neurons, perhaps acting via acy-1 (PubMed:30024377). Involved in modulating mate searching behavior independent of nutritional status (PubMed:18390545, PubMed:22579613, PubMed:23143519, PubMed:14551910). In the presence of food, plays a role in initiating and extending exploratory roaming behavior, perhaps acting in AIY, RIM, RIA, and other neurons, in opposition to 5-hydroxytryptamine (serotonin) signaling (PubMed:23972393). Involved in mediating arousal from the sleep-like state called lethargus, which occurs during molting between larval and adult stages, in part by regulating touch sensitivity (PubMed:18390545, PubMed:23764289). May play a role in circadian rhythms of locomotor activity (PubMed:26113231). G-protein coupled receptor which is activated by neuropeptides PDF-1 and PDF-2 (PubMed:18390545). Probably acts through the G-alpha(s) type of G proteins to elevate cAMP levels (PubMed:18390545). G-protein coupled receptor which is activated by neuropeptides PDF-1 and PDF-2 (PubMed:18390545). Probably acts through the G-alpha(s) type of G proteins to elevate cAMP levels (PubMed:18390545). G-protein coupled receptor which is activated by neuropeptides PDF-1 and PDF-2; however, activation is lower compared to isoforms a and b (PubMed:18390545). Probably inhibits cAMP levels through the G-alpha(i/o) type of G proteins (PubMed:18390545). Expression was observed in the mechanosensory neuron pairs PLM, ALM, FLP, OLQD, and OLQV, the chemosensory neurons PHA, PHB, RMEV, the ring motor neurons RMED, and the pharyngeal interneuron pair I1 (PubMed:18390545). Expression in sensory neurons PHA, PQR and URY are responsible for mate searching behavior (PubMed:23143519). Expressed in AIY, RIM, RIA, and other neurons. Expressed in both hermaphrodites and males at the L4 stage in the head, body wall muscle cells and tail. Disrupted locomotion (unc); decreased speed, increased number of reversals and loss of mate searching behavior (PubMed:14551910, PubMed:22579613, PubMed:23143519). RNAi-mediated knockdown causes reduced expression of TGFbeta-like daf-7 in ASJ chemosensory neurons (PubMed:30024377). Belongs to the G-protein coupled receptor 2 family.