Opening of glutamate receptor channel to subconductance levels.

ABSTRACT: Ionotropic glutamate receptors (iGluRs) are tetrameric ligand-gated ion channels that open their pores in response to binding of the agonist glutamate^1-3. An ionic current through a single iGluR channel shows up to four discrete conductance levels (O1-O4)^4-6. Higher conductance levels have been associated with an increased number of agonist molecules bound to four individual ligand-binding domains (LBDs)^6-10. Here we determine structures of a synaptic complex of AMPA-subtype iGluR and the auxiliary subunit γ2 in non-desensitizing conditions with various occupancy of the LBDs by glutamate. We show that glutamate binds to LBDs of subunits B and D only after it is already bound to at least the same number of LBDs that belong to subunits A and C. Our structures

SUBMITTER: Yelshanskaya MV 

PROVIDER: S-EPMC9068512 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature