ShadowR: a novel chromoprotein with reduced non-specific binding and improved expression in living cells

Sci Rep. 2019 Aug 19;9(1):12072. doi: 10.1038/s41598-019-48604-4.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biophysical Phenomena*
  • Fluorescence Resonance Energy Transfer
  • Fluorescence*
  • Gene Expression / genetics
  • Green Fluorescent Proteins / chemistry
  • Green Fluorescent Proteins / genetics
  • HeLa Cells
  • Humans
  • Luminescent Proteins / chemistry*
  • Luminescent Proteins / genetics
  • Microscopy, Fluorescence / methods*
  • Protein Binding / genetics

Substances

  • Luminescent Proteins
  • Green Fluorescent Proteins