Cited by 235Neuroscience and Neuropharmacology ResearchIon channel regulation and functionNicotinic Acetylcholine Receptors Study

Multiple Structural Elements Determine Subunit Specificity of Mg2+Block in NMDA Receptor Channels

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Kuner, Thomas, Schoepfer, Ralf·1996·The Journal of Neuroscience

Abstract

In NMDA receptor channels, subtype-specific differences of Mg 2+block are determined by the NR2 subunits. Channels assembled from the NR1-NR2A or NR1-NR2B subunits are blocked more strongly than channels formed by the NR1-NR2C or NR1-NR2D subunits, predominantly reflecting a difference in voltage dependence. A determinant of Mg 2+block common to the NR2 subunits is located in the M2 domain (N-site or Q/R/N-site). However, subunit-specific differences of block suggested that additional structural elements exist. Chimeric NR2 subunits were constructed by replacing segments of the least sensitive NR2C subunit with homologous segments of the most sensitive NR2B subunit. Mutant NR2 subunits were coexpressed with wild-type NR1 in Xenopus oocytes, and Mg 2+block was quantified. Replacement of the entire M1–M4 region resulted in a chimera with a sensitivity of Mg 2+block similar to that of the NR2B wild type. Replacing smaller segments or introducing point mutations did not generate channels with Mg 2+block characteristic of NR2B wild type. However, combining in a single chimera three small segments (M1, M2–M3 linker, M4), each independently mediating an increase in Mg 2+block, produced channels close to NR2B wild type. Thus, differences in Mg 2+block as controlled by the NR2 subunits cannot be explained by a single structural determinant in addition to the N-site. Moreover, three elements of the NR2 subunit are the major determinants of subtype-specific differences of Mg 2+block in heteromeric NMDA receptor channels.

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Crossref · 10.1523/jneurosci.16-11-03549.1996

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  • The extent of Mg2+ block and Ca2+ permeability depends on NMDAR subunit composition.

    “Notably, the magnitude of Mg2+ block and Ca2+ permeability is dependent on the subunit composition of the receptor”

    From Mechanisms of ketamine and its metabolites as antidepressants (2022) · cites this paper as Kuner & Schoepfer, 1996

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  1. Ausuhcl FM, Brent R, Kingston RE, Moore DD, Scidman JG, Smith JA, Struhl K (1995) Mutagcncsis of cloned DNA. In: Current protocols in molecular biology, Chap 8. (Jansscn K, cd). New York: Wiley.

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Authors
Kuner, T., & Schoepfer, R.
Affiliations
Heidelberg University (DE)
Venue
The Journal of Neuroscience
Published
1996-06-01
Volume
16
Issue
11
Pages
3549-3558
ISSN
  • 0270-6474 (ISSN-L)
  • 1529-2401
OpenAlex
W1530479094
Cited by
235
References
49
Citations by year
2026: 3 · 2025: 5 · 2024: 7 · 2023: 5 · 2022: 5 · 2021: 8 · 2020: 9 · 2019: 5 · 2018: 6 · 2017: 4 · 2016: 10 · 2015: 3 · 2014: 8 · 2013: 9 · 2012: 10
FWCI
4.60
Type
journal article
Language
en
Open access
Locations
  • Journal of Neuroscience (publishedVersion, cc-by-nc-sa)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Max Planck Institute for Plasma Physics (submittedVersion)
  • UCL Discovery (University College London) (submittedVersion)
  • Max Planck Digital Library (submittedVersion)
  • MPG.PuRe (Max Planck Society) (submittedVersion)
Funders
Wellcome Trust
Topics
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neuropharmacology Research
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Ion channel regulation and function
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Nicotinic Acetylcholine Receptors Study
Keywords
NMDA receptor channels, Mg2+ block, NR2 subunits, subunit specificity, NR2B, NR2C, NR1, chimeric subunits, voltage dependence, heteromeric channels, ion channel structure
MeSH terms
Amino Acid Sequence, Animals, Female, Ion Channels, Magnesium, Microelectrodes, Molecular Sequence Data, Oocytes, Recombinant Fusion Proteins, Sensitivity and Specificity, Xenopus, Receptors, N-Methyl-D-Aspartate, Patch-Clamp Techniques

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