title: Sodium channels as gateable non-photonic sensors for membrane-delimited reactive species.
abstract: Reactive oxygen species (ROS) and reactive oxygen intermediates (ROI) play crucial roles in physiological processes. While excessive ROS damages cells, small fluctuations in ROS levels represent physiological signals important for vital functions. Despite the physiological importance of ROS, many fundamental questions remain unanswered, such as which types of ROS occur in cells, how they distribute inside cells, and how long they remain in an active form. The current study presents a ratiometric sensor of intracellular ROS levels based on genetically engineered voltage-gated sodium channels (roNaV). roNaV can be used for detecting oxidative modification that occurs near the plasma membrane with a sensitivity similar to existing fluorescence-based ROS sensors. Moreover, roNaV has several advantages over traditional sensors because it does not need excitation light for sensing, and thus, can be used to detect phototoxic cellular modifications. In addition, the ROS dynamic range of roNaV is easily manipulated in real time by means of the endogenous channel inactivation mechanism. Measurements on ROS liberated from intracellular Lucifer Yellow and genetically encoded KillerRed have revealed an assessment of ROS lifetime in individual mammalian cells. Flashlight-induced ROS concentration decayed with two major time constants of about 10 and 1000 ms.
authors: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena, & Jena University Hospital, Jena, Germany.
authors: Navin K
authors: NK
authors: Ojha
authors: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena, & Jena University Hospital, Jena, Germany.
authors: Ehsan
authors: E
authors: Nematian-Ardestani
authors: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena, & Jena University Hospital, Jena, Germany.
authors: Sophie
authors: S
authors: Neugebauer
authors: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena, & Jena University Hospital, Jena, Germany.
authors: Benjamin
authors: B
authors: Borowski
authors: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena, & Jena University Hospital, Jena, Germany; The National Institute of Laser Enhanced Science, Cairo University, Cairo, Egypt.
authors: Ahmed
authors: A
authors: El-Hussein
authors: Department of Physiology, University of Pennsylvania, Philadelphia, USA.
authors: Toshinori
authors: T
authors: Hoshi
authors: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena, & Jena University Hospital, Jena, Germany.
authors: Enrico
authors: E
authors: Leipold
authors: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena, & Jena University Hospital, Jena, Germany. Electronic address: Stefan.H.Heinemann@uni-jena.de.
authors: Stefan H
authors: SH
authors: Heinemann
mesh_terms: D002462:Cell Membrane / Q000378:metabolism*; D002478:Cells, Cultured; D057809:HEK293 Cells; D006801:Humans; D015640:Ion Channel Gating; D009154:Mutation; D010084:Oxidation-Reduction; D017785:Photons; D017382:Reactive Oxygen Species / Q000378:metabolism*; D061566:Voltage-Gated Sodium Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D061566:Voltage-Gated Sodium Channels
keywords: Channel gating; Channel inactivation; Oxidation; ROS sensor; Sodium channel