Objective Our understanding of ion channel operation is limited to inferences based on functional data and to static snapshots of their structures where they are available. Cyclic nucleotide-modulated channels and calcium-activated K+ channels play crucial roles in a myriad of physiological processes ranging from signal transduction to neuronal excitability. The binding of ligands to specialized intracellular domains modulates the opening/closing (gating) equilibrium of these channels. Both the high resolution structures - in open and closed conformation - of these channels and the precise mechanism of ligand-mediated channel activation are unknown. The present proposal aims to understand the mechanism of ion channel modulation by ligands. To accomplish this goal we will utilize prokaryotic homologues of these channels reconstituted in artificial membranes. High-speed atomic force microscopy (HS-AFM) will allow us to directly observe individual ion channel molecules in action at high spatiotemporal resolution and in physiological conditions. Through UV-laser pulses caged ligands (caged-Ca2+ or caged-cAMP) will be liberated during HS-AFM imaging and the conformational changes associated to ligand binding monitored in real time. Differences between liganded and unliganded channel structures will provide insight into the mechanism of ligand gating. The obtained data will be compared to single channel current recordings under comparable conditions. Fields of science natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsnatural sciencesphysical sciencesatomic physicsnatural sciencesphysical sciencesopticsmicroscopynatural sciencesbiological sciencesmolecular biologymolecular neurosciencenatural sciencesbiological sciencesmolecular biologystructural biology Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2014-EF - Marie Skłodowska-Curie Individual Fellowships (IF-EF) Call for proposal H2020-MSCA-IF-2014 See other projects for this call Funding Scheme MSCA-IF-EF-ST - Standard EF Coordinator INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE Net EU contribution € 173 076,00 Address Rue de tolbiac 101 75654 Paris France See on map Region Ile-de-France Ile-de-France Paris Activity type Research Organisations Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00