Receptor for prostacyclin (prostaglandin I2 or PGI2). The activity of this receptor is mediated by G(s) proteins which activate adenylate cyclase. Interacts (non-isoprenylated C-terminus) with PDZK1. Isoprenylation does not influence ligand binding but is required for efficient coupling to the effectors adenylyl cyclase and phospholipase C. Belongs to the G-protein coupled receptor 1 family. Palmitoylation of either Cys-308 or Cys-311 was reported to be sufficient to maintain functional coupling to G(s) proteins and signaling (PubMed:12488443). However, this publication was retracted due to figure duplication.