mKusabira Orange Fused to Mouse Profilin
Kusabira Orange was one of the first yellow-orange fluorescent proteins identified in various Anthozoa species. Through site-directed and random mutagenesis of Kusabira Orange researchers developed a monomeric form of the protein known as mKusabira Orange (mKO). In addition to peak excitation and emission wavelengths of 548 and 559 nanometers, respectively, mKO exhibits brightness approximately equivalent to EGFP and excellent photostability under widefield illumination. The digital image above demonstrates the localization of a fusion between mKusabira Orange and mouse profilin. In the cell, most profilin is found bound to actin, though the small protein has more than 50 binding partners. Through its interaction with actin, profilin plays an important role in cell structure and motility.