mTurquoise Fused to Human Fibrillarin
mTurquoise is a high-performance derivative of enhanced cyan fluorescent protein (ECFP). The spectral properties of mTurquoise and ECFP are similar with excitation and emission peaks at approximately 435 and 475 nanometers, respectively. Nucleoli were visualized in the digital image above by fusing mTurquoise to human fibrillarin. Fibrillarin is a nucleolar protein originally discovered in Baker's yeast, to which it is essential for viability. Human fibrillarin is a component of the nucleolar small nuclear ribonucleoprotein (snRNP) particle thought to be involved in the initial step of processing pre-ribosomal (r)RNA.