W2466.48 Opens a Gate for a Continuous Intrinsic Water Pathway during Activation of the Adenosine A2A Receptor |
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Authors: | Dr Shuguang Yuan Dr Zhenquan Hu Prof Slawomir Filipek Prof Horst Vogel |
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Institution: | 1. Laboratory of Physical Chemistry of Polymers and Membranes, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland);2. Department of Pharmaceutical Sciences, University of Basel (Switzerland);3. Laboratory of Biomodeling, Faculty of Chemistry & Biological and Chemical Research Centre, University of Warsaw, Warsaw (Poland) |
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Abstract: | The question how G‐protein‐coupled receptors transduce an extracellular signal by a sequence of transmembrane conformational transitions into an intracellular response remains to be solved at molecular detail. Herein, we use molecular dynamics simulations to reveal distinct conformational transitions of the adenosine A2A receptor, and we found that the conserved W2466.48 residue in transmembrane helix TM6 performs a key rotamer toggle switch. Agonist binding induces the sidechain of W2466.48 to fluctuate between two distinct conformations enabling the diffusion of water molecules from the bulk into the center of the receptor. After passing the W2466.48 gate, the internal water molecules induce another conserved residue, Y2887.53, to switch to a distinct rotamer conformation establishing a continuous transmembrane water pathway. Further, structural changes of TM6 and TM7 induce local structural changes of the adjacent lipid bilayer. |
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Keywords: | G‐protein‐coupled receptor molecular dynamics simulations molecular switches signal transduction water channel |
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