Use of blue fluorescent protein Electra2 for live-cell imaging in Dictyostelium discoideum

Because of its good spectral separation from green (GFP) and red (RFP) fluorescent proteins, blue fluorescent protein (BFP) is essential for multicolor live cell imaging. However, the commonly used bright mTagBFP2 strongly perturbs the cellular localization of Lifeact, an F-actin marker. As an alternative, we tested the expression of Electra2 in Dictyostelium . Both standalone and as a fusion tag to Lifeact, HistoneH1, or the Akt/PKB PH domain, Electra2 showed brightness comparable to that of mTagBFP2, with intracellular localization patterns consistent with those of GFP and RFP. Electra2 is a promising BFP of choice for studying actin and other targets.