Novel completely genetically encoded photosensitiser, KillerRed, opens up new possibilities for precise light-induced protein inactivation and cell killing in vivo
Photosensitisers are chromophores that generate reactive oxygen species (ROS) upon light irradiation.
They find use for precise inactivation of selected proteins in chromophore-assisted laser inactivation (Cali) technique and for the light-induced cell killing, for example in photodynamic therapy.
All known to date photosensitisers are chemical compounds that must be introduced into living systems exogenously.
This limitation severely constricts the area of their applications.
KillerRed developed on the basis of the Anthomedusae chromoprotein is a first entirely genetically encoded photosensitiser.
Unlike chemical analogues, KillerRed can be directly expressed by target cells, both individually and in fusion with a target protein.
It shows no cell toxic effects before light activation.
Upon green light irradiation KillerRed generates reactive oxygen species (ROS) that damage the neighboring molecules.
KillerRed is a dimeric red fluorescent protein with successful performance in many fusions including that with cytoplasmic beta-actin, fibrillarin, dopamine transporter, etc.
Moreover, KillerRed has proven availability to create stably transfected cell lines.
KillerRed phototoxicity is induced by green light irradiation at 540-580nm and depends on light intensity, irradiation time and KillerRed concentration.
In Cali, mild illumination of KillerRed-tagged protein for a limited time results in precise inactivation of this protein only.
Upon the more prolonged and intensive irradiation KillerRed can be effectively used for damaging the organelles and killing the target cells.
Evrogen offers a set of expression vectors for KillerRed bacterial and eukaryotic expression and fusion preparation.
