roNaV: A nonphotonic gateable ROS sensor

Ojha, N.K., E. Nematian-Ardestani, S. Neugebauer, B. Borowski, A. El-Hussein, T. Hoshi, E. Leipold, S.H. Heinemann. Sodium channels as gateable non-photonic sensors for membrane-delimited reactive species. Biochimica et Biophysica Acta - Biomembranes (2014) 1838: 1412-1419

Response of roGFP2 (top) and the ratiometric roNaV signal (bottom) to blue light. At -50 mV roNaV is inactivated and, thus, protected from ROS attack.
Illustration: FSU Biophysik

The current study presents a ratiometric sensor of intracellular reactive species (RS) levels based on genetically engineered voltage-gated sodium channels (roNa_V). roNa_V can be used for detecting oxidative modification that occurs near the plasma membrane with a sensitivity similar to existing fluorescence-based sensors. roNa_V does not need excitation light for sensing, and thus, can be used to detect phototoxic cellular modifications. The RS dynamic range of roNa_V is easily manipulated by means of the endogenous channel inactivation mechanism. Moreover, roNa_V was used to assess RS lifetime in individual mammalian cells.