Guanylate cyclase involved in the production of the second messenger cGMP (By similarity). Unlike other guanylate cyclases expressed in ASE neurons, may not play a role in chemotaxis responses to salt ions mediated by ASE sensory neurons (PubMed:19523832). GTP = 3',5'-cyclic GMP + diphosphate Expressed in both ASEL and ASER neurons during early embryonic stages and becomes specifically expressed in ASER neuron in early larval stage. The protein kinase domain is predicted to be catalytically inactive. Belongs to the adenylyl cyclase class-4/guanylyl cyclase family.