@article{8f0b4d2d517c4eb28a420ff7f55dbe34,
title = "Structural dynamics of the GluK3-kainate receptor neurotransmitter binding domains revealed by cryo-EM",
abstract = "Kainate receptors belong to the ionotropic glutamate receptor family and play critical roles in the regulation of synaptic networks. The kainate receptor subunit GluK3 has unique functional properties and contributes to presynaptic facilitation at the hippocampal mossy fiber synapses along with roles at the post-synapses. To gain structural insights into the unique functional properties and dynamics of GluK3 receptor, we imaged them via electron microscopy in the apo-state and in complex with either agonist kainate or antagonist UBP301. Our analysis of all the GIuK3 full-length structures not only provides insights into the receptor transitions between desensitized and closed states but also reveals a {"}non-classical{"} conformation of neurotransmitter binding domain in the closed-state distinct from that observed in AMPA and other kainate receptor structures. We show by molecular dynamics simulations that Asp759 influences the stability of the LBD dimers and hence could be responsible for the observed conformational variability and dynamics of the GIuK3 via electron microscopy. Lower dimer stability could explain faster desensitization and low agonist sensitivity of GluK3. In overview, our work helps to associate biochemistry and physiology of GluK3 receptors with their structural biology and offers structural insights into the unique functional properties of these atypical receptors. (C) 2020 Elsevier B.V. All rights reserved.",
keywords = "Glutamate receptor, Cryo-electron microscopy, Kainate, GLUTAMATE-RECEPTOR, GLUK3, AMPA, IMPLEMENTATION, GLUR7",
author = "Jyoti Kumari and Bendre, {Ameya D.} and Sumedha Bhosale and Rajesh Vinnakota and Burada, {Ananth P.} and Giancarlo Tria and Ravelli, {Raimond B. G.} and Peters, {Peter J.} and Manali Joshi and Janesh Kumar",
note = "Funding Information: The research program in our laboratory is supported by the Wellcome Trust DBT India Alliance ( IA/I/13/2/501023 ) and Centre of Excellence grant BT/PR15450/COE/34/46/2016 from Department of Biotechnology, India . Jyoti Kumari thanks University Grants Commission, India for senior research fellowship. R.V. is supported by SERB -N-PDF fellowship ( N-PDF/2016/002621 ). A.D.B is supported by a research associate fellowship by DBT, India. We thank Frank Nijpels for EM grid vitrification. We also acknowledge the help of Giancarlo Tria and Abril Gijsbers in the extensive screening of suitable conditions for cryo and negative stain grid preparation. We thank Dr. Carmen Lopez-Iglesias and microscopy core lab team at M4I for facilitating this work. Dr. Mark L. Mayer kindly gifted the various iGluR constructs that were sub-cloned and used for construct optimization and mutational studies. Dr. Eric Gouaux kindly provided the pEGBacMam vector. Funding Information: The research program in our laboratory is supported by the Wellcome Trust DBT India Alliance (IA/I/13/2/501023) and Centre of Excellence grant BT/PR15450/COE/34/46/2016 from Department of Biotechnology, India. Jyoti Kumari thanks University Grants Commission, India for senior research fellowship. R.V. is supported by SERB-N-PDF fellowship (N-PDF/2016/002621). A.D.B is supported by a research associate fellowship by DBT, India. We thank Frank Nijpels for EM grid vitrification. We also acknowledge the help of Giancarlo Tria and Abril Gijsbers in the extensive screening of suitable conditions for cryo and negative stain grid preparation. We thank Dr. Carmen Lopez-Iglesias and microscopy core lab team at M4I for facilitating this work. Dr. Mark L. Mayer kindly gifted the various iGluR constructs that were sub-cloned and used for construct optimization and mutational studies. Dr. Eric Gouaux kindly provided the pEGBacMam vector. The authors declare no competing interests. Publisher Copyright: {\textcopyright} 2020 Elsevier B.V.",
year = "2020",
month = apr,
day = "15",
doi = "10.1016/j.ijbiomac.2020.01.282",
language = "English",
volume = "149",
pages = "1051--1058",
journal = "International Journal of Biological Macromolecules",
issn = "0141-8130",
publisher = "Elsevier",
}