Guanylate cyclase involved in the production of the second messenger cGMP (By similarity). Involved in the sensing of CO2 levels and acidity by the BAG neurons. May act as a direct receptor for CO2 and H+ (PubMed:21173231, PubMed:24240097). GTP = 3',5'-cyclic GMP + diphosphate Localizes in cilium of sensory neurons. Expressed in BAG sensory neurons. The protein kinase domain is predicted to be catalytically inactive. Belongs to the adenylyl cyclase class-4/guanylyl cyclase family.