A genetically encoded photosensitizer

Nat Biotechnol. 2006 Jan;24(1):95-9. doi: 10.1038/nbt1175. Epub 2005 Dec 20.


Photosensitizers are chromophores that generate reactive oxygen species (ROS) upon light irradiation. They are used for inactivation of specific proteins by chromophore-assisted light inactivation (CALI) and for light-induced cell killing in photodynamic therapy. Here we report a genetically encoded photosensitizer, which we call KillerRed, developed from the hydrozoan chromoprotein anm2CP, a homolog of green fluorescent protein (GFP). KillerRed generates ROS upon irradiation with green light. Whereas known photosensitizers must be added to living systems exogenously, KillerRed is fully genetically encoded. We demonstrate the utility of KillerRed for light-induced killing of Escherichia coli and eukaryotic cells and for inactivating fusions to beta-galactosidase and phospholipase Cdelta1 pleckstrin homology domain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cell Line
  • Cell Proliferation / radiation effects
  • Cell Survival / radiation effects
  • Escherichia coli / physiology
  • Escherichia coli / radiation effects*
  • Green Fluorescent Proteins / genetics*
  • Green Fluorescent Proteins / metabolism*
  • Humans
  • Kidney / cytology*
  • Kidney / radiation effects*
  • Light
  • Molecular Sequence Data
  • Photosensitizing Agents / metabolism*
  • Protein Engineering


  • Photosensitizing Agents
  • killer red protein, Anthomedusae
  • Green Fluorescent Proteins

Associated data

  • GENBANK/AY969116