title: Imaging calcium and redox signals using genetically encoded fluorescent indicators.
abstract: Calcium and redox signals are presently established as essential regulators of many cellular processes. Nevertheless, we are still far from fully understanding the physiological and pathological importance of these universal second messengers. It is becoming increasingly apparent that many cellular functions are not regulated by global changes in the abundance of Ca(2+) ions and/or reactive oxygen and nitrogen species (ROS and RNS), but by the formation of transient local micro-domains or by signaling limited to a particular cellular compartment. Therefore, it is essential to identify and quantify Ca(2+) and redox signals in single cells with a high spatial and temporal resolution. The best tools for this purpose are the genetically encoded fluorescent indicators (GEFI). These protein sensors can be targeted into different cellular compartments, feature different colors, can be used to establish transgenic animal models, and are relatively inert to the cellular environment. Based on the chemical properties of Ca(2+) and ROS/RNS, currently more sensors exist for the detection of Ca(2+)- than for redox signals. Here, we shortly describe the most popular genetically encoded fluorescent Ca(2+) and redox indicators, discuss advantages and disadvantages based on our experience, show examples of different applications, and thus provide a brief guide that will help scientists choose the right combination of Ca(2+) and redox sensors to answer specific scientific questions.
authors.affiliation: Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany.
authors.forename: Christine S
authors.initials: CS
authors.lastname: Gibhardt
authors.affiliation: Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany.
authors.forename: Katharina M
authors.initials: KM
authors.lastname: Zimmermann
authors.affiliation: Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia.
authors.forename: Vsevolod V
authors.initials: VV
authors.lastname: Belousov
authors.affiliation: Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany. Electronic address: ivan.bogeski@uks.eu.
authors.forename: Ivan
authors.initials: I
authors.lastname: Bogeski
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D017930:Genes, Reporter; D006801:Humans; D021621:Imaging, Three-Dimensional; D010084:Oxidation-Reduction; D015398:Signal Transduction
chemical_list: D005456:Fluorescent Dyes; D002118:Calcium
keywords: Calcium; Fluorescence; GEFI; H(2)O(2); Imaging; Microscopy; ROS; Redox