Related Experiment Video
Updated: Jan 20, 2026

Detection of Intracellular Gene Expression in Live Cells of Murine, Human and Porcine Origin Using Fluorescence-labeled Nanoparticles
Published on: November 13, 2015
ShadowR: a novel chromoprotein with reduced non-specific binding and improved expression in living cells
Hideji Murakoshi1,2, Hiroshi Horiuchi3,4, Takahiro Kosugi5,6,7
1Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan. murakosh@nips.ac.jp.
Abstract:
Here we developed an orange light-absorbing chromoprotein named ShadowR as a novel acceptor for performing fluorescence lifetime imaging microscopy-based Förster resonance energy transfer (FLIM-FRET) measurement in living cells. ShadowR was generated by replacing hydrophobic amino acids located at the surface of the chromoprotein Ultramarine with hydrophilic amino acids in order to reduce non-specific interactions with cytosolic proteins. Similar to Ultramarine, ShadowR shows high absorption capacity and no fluorescence. However, it exhibits reduced non-specific binding to cytosolic proteins and is highly expressed in HeLa cells. Using tandem constructs and a LOVTRAP system, we showed that ShadowR can be used as a FRET acceptor in combination with donor mRuby2 or mScarlet in HeLa cells. Thus, ShadowR is a useful, novel FLIM-FRET acceptor.
More Related Videos
Related Concept Videos
Cell Specific Gene Expression
Cell Specific Gene Expression
The Equilibrium Binding Constant and Binding Strength
mRNA Stability and Gene Expression
Cis-acting Elements involved in mRNA stability
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Conserved Binding Sites
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally...

