Radial symmetry in a chimeric glutamate receptor pore

Timothy J. Wilding, Melany N. Lopez, James E. Huettner

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


Ionotropic glutamate receptors comprise two conformationally different A/C and B/D subunit pairs. Closed channels exhibit fourfold radial symmetry in the transmembrane domain (TMD) but transition to twofold dimer-of-dimers symmetry for extracellular ligand binding and N-terminal domains. Here, to evaluate symmetry in open pores we analysed interaction between the Q/R editing site near the pore loop apex and the transmembrane M3 helix of kainate receptor subunit GluK2. Chimeric subunits that combined the GluK2 TMD with extracellular segments from NMDA receptors, which are obligate heteromers, yielded channels made up of A/C and B/D subunit pairs with distinct substitutions along M3 and/or Q/R site editing status, in an otherwise identical homotetrameric TMD. Our results indicate that Q/R site interaction with M3 occurs within individual subunits and is essentially the same for both A/C and B/D subunit conformations, suggesting that fourfold pore symmetry persists in the open state.

Original languageEnglish
Article number3349
JournalNature communications
StatePublished - Feb 24 2014


Dive into the research topics of 'Radial symmetry in a chimeric glutamate receptor pore'. Together they form a unique fingerprint.

Cite this