G-protein coupled receptor. G-protein coupled receptor for flp-13 RFamide neuropeptides in vitro (PubMed:28094002). Upon activation by flp-13 RFamide neuropeptides, promotes sleep in response to cellular stress also known as stress-induced sleep (SIS), probably by inhibiting the activity of wake-promoting neurons (PubMed:28094002). Expressed in head neurons including the RID neuron and the paired AIY neurons, and in tail neurons including the paired PHA and PHB neurons (PubMed:28094002). Not expressed in AVE and AVA neurons (PubMed:28094002). Belongs to the G-protein coupled receptor 1 family.