Nano-lantern(cAMP-1.6) is a genetically encoded luminescent cAMP sensor. It consists of a cAMP-binding motif from the Homo sapiens RAPGEF3 (Epac1) gene (residues 170-327, with a Q270E amino acid substitution) inserted at the 228/229 position into the 'Nano-lantern' luminescent protein (Nano-lantern is a fusion of enhanced Renilla luciferase (RLuc8) and Venus) (PMID:23232392).