Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Bischof, H.
Development, characterization and application of novel genetically encoded, fluorescent potassium ion indicators
PhD-Studium (Doctor of Philosophy); Humanmedizin; [ Dissertation ] Graz Medical University; 2019. pp.105.
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- Autor*innen der Med Uni Graz:
- Bischof Helmut
- Betreuer*innen:
- Graier Wolfgang
- Groschner Klaus
- Malli Roland
- Altmetrics:
- Abstract:
- The maintenance of intra- and extracellular potassium ion (K+) concentrations is important for many cellular processes and biological functions. Based on the urgent need of detection methods for K+, due to the lack of applicable probes, we have recently developed Förster resonance energy transfer (FRET)- based K+ sensitive probes, allowing the real-time visualization of intra- and extracellular K+ dynamics. These probes, referred to as GEPIIs (genetically encoded potassium ion indicators), consist of a bacteria-derived K+ binding protein, Kbp, sandwiched by a cyan and a yellow fluorescent protein variant. Upon K+ binding to these chimeras, FRET-signals increase dramatically, yielding a high signal to noise ratio. Recombinant GEPIIs are suitable for the quantification of K+ levels in diverse bodily fluids in a fast and convenient manner. Moreover, the recombinant protein proved suitable for monitoring cell viability and cell growth with high spatial and temporal resolution. In addition, purified GEPIIs can be applied in vivo for the visualization of extracellular K+ dynamics in tissues of living animals. Expression of GEPIIs in cells allows hitherto unfeasible real-time detection of subcellular K+ dynamics. Our data highlight organelle specific K+ fluxes in response to cell depolarization. Altogether, our data emphasize that GEPIIs are suitable for diverse K+ assays and will open new avenues for live-cell K+ imaging in future.