• Home
  • Search Results
  • Structural Basis of the Proton Sensitivity of Human GluN1-GluN2A NMDA Receptors.

Structural Basis of the Proton Sensitivity of Human GluN1-GluN2A NMDA Receptors.

Cell reports (2018-12-28)
Jin-Bao Zhang, Shenghai Chang, Pan Xu, Miao Miao, Hangjun Wu, Youyi Zhang, Tongtong Zhang, Han Wang, Jilin Zhang, Chun Xie, Nan Song, Cheng Luo, Xing Zhang, Shujia Zhu
ABSTRACT

N-methyl-D-aspartate (NMDA) receptors are critical for synaptic development and plasticity. While glutamate is the primary agonist, protons can modulate NMDA receptor activity at synapses during vesicle exocytosis by mechanisms that are unknown. We used cryo-electron microscopy to solve the structures of the human GluN1-GluN2A NMDA receptor at pH 7.8 and pH 6.3. Our structures demonstrate that the proton sensor predominantly resides in the N-terminal domain (NTD) of the GluN2A subunit and reveal the allosteric coupling mechanism between the proton sensor and the channel gate. Under high-pH conditions, the GluN2A-NTD adopts an "open-and-twisted" conformation. However, upon protonation at the lower pH, the GluN2A-NTD transits from an open- to closed-cleft conformation, causing rearrangements between the tetrameric NTDs and agonist-binding domains. The conformational mobility observed in our structures (presumably from protonation) is supported by molecular dynamics simulation. Our findings reveal the structural mechanisms by which protons allosterically inhibit human GluN1-GluN2A receptor activity.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Phenylmethanesulfonyl fluoride, ≥98.5% (GC)
Sigma-Aldrich
Sodium butyrate, 98%
Sigma-Aldrich
Pepstatin A, microbial, ≥90% (HPLC)
Sigma-Aldrich
2,2-Dimethyl-1,3-propanediol, 99%
Sigma-Aldrich
Cholesteryl hemisuccinate
Sigma-Aldrich
Aprotinin from bovine lung, BioUltra, 3-8 TIU/mg solid, ≥98% (SDS-PAGE)
Sigma-Aldrich
Cholesteryl hemisuccinate tris salt, anionic detergent
Sigma-Aldrich
Leupeptin, BioUltra, microbial, ≥95% (HPLC)
Sigma-Aldrich
Anti-NMDAR2A Antibody, Chemicon®, from rabbit