Plasmids for C-terminal tagging in Saccharomyces cerevisiae that contain improved GFP proteins, Envy and Ivy

Green fluorescent protein (GFP) has become an invaluable tool in biological research. Many GFP variants have been created that differ in brightness, photostability, and folding robustness. We have created two hybrid GFP variants, Envy and Ivy, which we placed in a vector for the C-terminal tagging of yeast proteins by PCR-mediated recombination. The Envy GFP variant combines mutations found in the robustly folding SuperfolderGFP and GFP, while the Ivy GFP variant is a hybrid of GFP and the yellow-green GFP variant, Clover. We compared Envy and Ivy to EGFP, SuperfolderGFP and GFP and found that Envy is brighter than the other GFP variants at both 30 degrees C and 37 degrees C, while Ivy is the most photostable. Envy and Ivy are recognized by a commonly used anti-GFP antibody, and both variants can be immunoprecipitated using the GFP TRAP Camelidae antibody nanotrap technology. Because Envy is brighter than the other GFP variants and is as photostable as GFP, we suggest that Envy should be the preferred GFP variant, while Ivy may be used in cases where photostability is of the utmost importance. The GenBank Accession No. for Envy is KM891731, for Ivy is KM891732 and for the yeast optimized GFP described in this paper is KM891733. Copyright (c) 2015 John Wiley & Sons, Ltd.