Key negative regulator of Shh signaling during neural tube development. Recruited to primary cilia and acts as a regulator of the PKA-dependent basal repression machinery in Shh signaling by increasing cAMP levels, leading to promote the PKA-dependent processing of gli3 into gli3r and repress the Shh signaling. In presence of shh, it is removed from primary cilia, preventing its activity and allowing activation of the Shh signaling (By similarity). Mainly localizes to primary cilium and is removed from primary cilia in presence of shh. Belongs to the G-protein coupled receptor 1 family.