Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz

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SHR Neuro Krebs Kardio Stoffw Microb Lipid

Lösung des offenen Rätsels von TRPC3 durch Photopharmakologie

Abstract
• Wider research context / theoretical framework: TRPC3 is a distinct member of TRPC family. This channel is expressed in excitable and non-excitable cells. By non-selectively conducting cations even at its resting state, TRPC3 promotes cellular processes in both health and disease. However, there are only a few modulators of this channel available. To precisely design new therapeutic ligands, it is of high importance to gain knowledge about TRPC3 protein structure and, consequently, its gating mechanism. Recently, two TRPC3 structures were revealed by cryo electron microscopy (cryo-EM). Nonetheless, neither of them captured open pore architecture. Hence, the open conformations is the critical missing piece of information to solve the TRPC3 gating puzzle. This knowledge is essential for comprehension of the molecular function of TRPC3 and definition of possible ligand binding sites to control this channel is health and, especially, disease.
• Hypotheses / research questions / objectives: Here, we propose to succeed in capturing open pore structures of TRPC3 by stabilizing and synchronizing the channels at a high open probability using photochromic ligands and in addition by preserving their lipid environment during the protein preparation for cryo-EM.
• Approach / methods: We will screen two expression systems for suitability to maintain TRPC3 in open conformation. We will utilize photopharmacological tools for a temporal control over TRPC3 gating during protein extraction and cryo-EM. Structural details obtained from cryo-EM will be followed by structure-guided mutagenesis and evaluated in a multifunctional live cell approach combining Ca2+ imaging and electrophysiology.
• Level of originality / innovation: With our project, we will introduce a novel approach to control protein conformations during cryo-EM by photoswitchable ligands. Our work will unravel TRPC3 open architecture and promote the development of new concepts for therapeutic targeting of these channels.
• Primary researchers involved: The research team will include profound experts in TRPC3 electrophysiology and Ca2+ signaling Dr. Oleksandra Tiapko and Dr. Klaus Groschner (Medical University of Graz, Austria), experts in membrane lipids Dr. Anita Emmerstorfer-Augustin (Graz University of Technology) and in structural biology and electron microscopy Dr. Christine Ziegler (University of Regensburg).
Schlagworte
Ca2+ kanal
Cryo-EM
Ionenkanal
Strukturbiologie
TRPC3
Projektleitung:
Tiapko Oleksandra
Laufzeit:
01.01.2022-31.10.2025
Programm:
FWF Einzelprojekt
Art der Forschung
Angewandte Forschung
Mitarbeiter*innen
Tiapko O., Projektleiter*in
Baron J., Projektmitarbeiter*in
Beteiligte MUG-Organisationseinheiten
Lehrstuhl für Medizinische Physik und Biophysik
Projektpartner
Graz University of Technology, Österreich
University of Graz, Österreich
University of Regensburg, Deutschland
Gefördert durch
FWF, Fonds zur Förderung der Wissenschaftlichen Forschung, Wien, Österreich

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