Plays a central role in social feeding behavior and oxygen sensation by synthesizing 3',5'-cyclic guanosine monophosphate (cGMP) from GTP. Oxygen, which binds to its heme-binding sites, probably regulates social behavior by modulating its activity. cGMP is a common second messenger in sensory transduction and is implicated in oxygen sensation. Indeed, C.elegans exhibits a strong behavioral preference for 5-12% oxygen, avoiding higher and lower oxygen levels; a higher level of oxygen inducing a naturally polymorphic social feeding behavior. Involved in avoidance of hyperoxia and for oxygen-induced aggregation and bordering, probably by mediating oxygen-sensing in URX, AQR and PQR sensory neurons. GTP = 3',5'-cyclic GMP + diphosphate Binds 1 or 2 heme groups per heterodimer. Regulated by molecular oxygen, which binds to the heme binding site. Probably not activated by nitric oxide (NO). Heterodimer; heterodimerizes with gcy-36, and possibly with other soluble guanylate cyclases. Enriched localization at the URX dendrite ending. Expressed in URX, AQR and PQR neurons. Also expressed in ALN, SDQ and BDU neurons, and variably in AVM, PLM and PLN neurons, pharyngeal and body wall muscles, and the excretory cell. There are two types of guanylate cyclases: soluble forms and membrane-associated receptor forms. Belongs to the adenylyl cyclase class-4/guanylyl cyclase family.