C-GLuc corresponds to the C-terminal part (residues 110-185) of the luciferase encoded by the Gaussia princeps Luc gene (UniProtKB:Q9BLZ2). If the C-GLuc split enzyme fragment is brought into close association with the complementary N-GLuc split enzyme fragment in vivo, a catalytically active enzyme may be reconstituted, which can emit bioluminescence in the presence of the coelenterazine substrate (PMID:40089621).