Fluorescent proteins from nonbioluminescent Anthozoa species

We have cloned six fluorescent proteins homologous to the green fluorescent protein (GFP) from Aequorea victoria, Two of these have spectral character istics dramatically different from GFP, emitting at yellow and red waveleng ths. All the proteins were isolated from nonbioluminescent reef corals, dem onstrating that GFP-like proteins are not always functionally linked to bio luminescence. The new proteins share the same beta-can fold first observed in GFP, and this provided a basis for the comparative analysis of structura l features important for fluorescence. The usefulness of the new proteins f or in vivo labeling was demonstrated by expressing them in mammalian cell c ulture and in mRNA microinjection assays in Xenopus embryos.