1
|
Hussain N, Apotikar A, Pidathala S, Mukherjee S, Burada AP, Sikdar SK, Vinothkumar KR, Penmatsa A. Cryo-EM structures of pannexin 1 and 3 reveal differences among pannexin isoforms. Nat Commun 2024; 15:2942. [PMID: 38580658 PMCID: PMC10997603 DOI: 10.1038/s41467-024-47142-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 03/19/2024] [Indexed: 04/07/2024] Open
Abstract
Pannexins are single-membrane large-pore channels that release ions and ATP upon activation. Three isoforms of pannexins 1, 2, and 3, perform diverse cellular roles and differ in their pore lining residues. In this study, we report the cryo-EM structure of pannexin 3 at 3.9 Å and analyze its structural differences with pannexin isoforms 1 and 2. The pannexin 3 vestibule has two distinct chambers and a wider pore radius in comparison to pannexins 1 and 2. We further report two cryo-EM structures of pannexin 1, with pore substitutions W74R/R75D that mimic the pore lining residues of pannexin 2 and a germline mutant of pannexin 1, R217H at resolutions of 3.2 Å and 3.9 Å, respectively. Substitution of cationic residues in the vestibule of pannexin 1 results in reduced ATP interaction propensities to the channel. The germline mutant R217H in transmembrane helix 3 (TM3), leads to a partially constricted pore, reduced ATP interaction and weakened voltage sensitivity. The study compares the three pannexin isoform structures, the effects of substitutions of pore and vestibule-lining residues and allosteric effects of a pathological substitution on channel structure and function thereby enhancing our understanding of this vital group of ATP-release channels.
Collapse
Affiliation(s)
- Nazia Hussain
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Ashish Apotikar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Shabareesh Pidathala
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
- St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Sourajit Mukherjee
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
- Department of Chemistry, The University of Chicago, Chicago, USA
| | - Ananth Prasad Burada
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Sujit Kumar Sikdar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Kutti R Vinothkumar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, 560065, India
| | - Aravind Penmatsa
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India.
| |
Collapse
|
2
|
Burada AP, Vinnakota R, Lambolez B, Tricoire L, Kumar J. Structural biology of ionotropic glutamate delta receptors and their crosstalk with metabotropic glutamate receptors. Neuropharmacology 2021; 196:108683. [PMID: 34181979 DOI: 10.1016/j.neuropharm.2021.108683] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/31/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
Abstract
Enigmatic orphan glutamate delta receptors (GluD) are one of the four classes of the ionotropic glutamate receptors (iGluRs) that play key roles in synaptic transmission and plasticity. While members of other iGluR families viz AMPA, NMDA, and kainate receptors are gated by glutamate, the GluD receptors neither bind glutamate nor evoke ligand-induced currents upon binding of glycine and D-serine. Thus, the GluD receptors were considered to function as structural proteins that facilitate the formation, maturation, and maintenance of synapses in the hippocampus and cerebellum. Recent work has revealed that GluD receptors have extensive crosstalk with metabotropic glutamate receptors (mGlus) and are also gated by their activation. The latest development of a novel optopharamcological tool and the cryoEM structures of GluD receptors would help define the molecular and chemical basis of the GluD receptor's role in synaptic physiology. This article is part of the special Issue on "Glutamate Receptors - Orphan iGluRs".
Collapse
Affiliation(s)
- Ananth Prasad Burada
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, 411007, India
| | - Rajesh Vinnakota
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, 411007, India
| | - Bertrand Lambolez
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| | - Ludovic Tricoire
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France.
| | - Janesh Kumar
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, 411007, India.
| |
Collapse
|
3
|
Burada AP, Vinnakota R, Bharti P, Dutta P, Dubey N, Kumar J. Emerging insights into the structure and function of ionotropic glutamate delta receptors. Br J Pharmacol 2020; 179:3612-3627. [DOI: 10.1111/bph.15313] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 12/22/2022] Open
Affiliation(s)
- Ananth Prasad Burada
- Laboratory of Membrane Protein Biology National Centre for Cell Science, NCCS Complex, S. P. Pune University Pune India
| | - Rajesh Vinnakota
- Laboratory of Membrane Protein Biology National Centre for Cell Science, NCCS Complex, S. P. Pune University Pune India
| | - Pratibha Bharti
- Laboratory of Membrane Protein Biology National Centre for Cell Science, NCCS Complex, S. P. Pune University Pune India
| | - Priyanka Dutta
- Laboratory of Membrane Protein Biology National Centre for Cell Science, NCCS Complex, S. P. Pune University Pune India
| | - Neelima Dubey
- Molecular Neuroscience Research Lab Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth Tathawade Pune 411033 India
| | - Janesh Kumar
- Laboratory of Membrane Protein Biology National Centre for Cell Science, NCCS Complex, S. P. Pune University Pune India
| |
Collapse
|
4
|
Burada AP, Vinnakota R, Kumar J. The architecture of GluD2 ionotropic delta glutamate receptor elucidated by cryo-EM. J Struct Biol 2020; 211:107546. [PMID: 32512155 DOI: 10.1016/j.jsb.2020.107546] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 12/20/2022]
Abstract
GluD2 receptor belongs to the orphan delta family of glutamate receptor ion channels. These receptors play key roles in synaptogenesis and synaptic plasticity and are associated with multiple neuronal disorders like schizophrenia, autism spectrum disorder, cerebellar ataxia, intellectual disability, paraplegia, retinal dystrophy, etc. Despite the importance of these receptors in CNS, insights into full-length GluD2 receptor structure is missing till-date. Here we report cryo-electron microscopy structure of the rat GluD2 receptor in the presence of calcium ions and the ligand 7-chlorokynurenic acid, elucidating its 3D architecture. The structure reveals a non-swapped architecture at the extracellular amino-terminal (ATD), and ligand-binding domain (LBD) interface similar to that observed in GluD1; however, the organization and arrangement of the ATD and LBD domains in GluD2 are unique. While our results demonstrate that non-swapped architecture is conserved in the delta receptor family, they also highlight the differences that exist between the two member receptors; GluD1 and GluD2.
Collapse
Affiliation(s)
- Ananth Prasad Burada
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra 411007, India
| | - Rajesh Vinnakota
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra 411007, India
| | - Janesh Kumar
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra 411007, India.
| |
Collapse
|
5
|
Burada AP, Vinnakota R, Kumar J. Cryo-EM structures of the ionotropic glutamate receptor GluD1 reveal a non-swapped architecture. Nat Struct Mol Biol 2020; 27:84-91. [PMID: 31925409 PMCID: PMC7025878 DOI: 10.1038/s41594-019-0359-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 11/27/2019] [Indexed: 01/06/2023]
Abstract
Ionotropic orphan delta receptors (GluD) are not gated by glutamate or
any other endogenous ligand but are grouped with ionotropic glutamate receptors
based on sequence similarity. GluD1 receptors play critical roles in
synaptogenesis, synapse maintenance and have been implicated in neuronal
disorders including schizophrenia, cognitive deficits, and cerebral ataxia. Here
we report cryo-electron microscopy structures of the rat GluD1 receptor
complexed with calcium and the ligand 7-chlorokynurenic acid, elucidating
molecular architecture and principles of receptor assembly. The structures
reveal a non-swapped architecture at the extracellular amino-terminal (ATD) and
ligand-binding domain (LBD) interface. This is in contrast to other families of
ionotropic glutamate receptors (iGluRs) where the dimer partners between the ATD
and LBD layers are swapped. Our results demonstrate that principles of
architecture and symmetry are not conserved between delta receptors and other
iGluRs and provide a molecular blueprint for understanding the functions of the
“orphan” class of iGluRs.
Collapse
Affiliation(s)
- Ananth Prasad Burada
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, India
| | - Rajesh Vinnakota
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, India
| | - Janesh Kumar
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, India.
| |
Collapse
|