TagRFP-T Fused to an Endosomal Targeting Peptide
TagRFP is a monomeric orange protein developed through site-directed mutagenesis of TurboRFP, which was originally cloned from Entacmaea quadricolor. The only drawback of TagRFP was found to be its relatively poor photostability. However, mutagenesis of TagRFP yielded an enhanced variant called TagRFP-T with photostability increased nearly 10-fold. The digital image above demonstrates the localization of a fusion between TagRFP-T and an endosomal targeting peptide. As can be seen in the image, endosomes are found scattered throughout eukaryotic cells, where they function as one of the primary sorting compartments of the endomembrane system. Molecules contained within endosomes can follow a variety of different pathways, such as being passed along to lysosomes for degradation or being recycled back to the plasma membrane or Golgi apparatus.