Format

Send to

Choose Destination
J Gen Physiol. 2020 Jan 6;152(1). pii: jgp.201912451. doi: 10.1085/jgp.201912451.

Mechanism of modulation of AMPA receptors by TARP-γ8.

Author information

1
Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX.
2
E. Carrillo and S.A. Shaikh contributed equally to this work and are listed in alphabetical order.
3
MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX.
4
Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY.
5
Department of Molecular Medicine, Cornell University, Ithaca, NY.

Abstract

Fast excitatory synaptic transmission in the mammalian central nervous system is mediated by glutamate-activated α-amino-5-methyl-3-hydroxy-4-isoxazole propionate (AMPA) receptors. In neurons, AMPA receptors coassemble with transmembrane AMPA receptor regulatory proteins (TARPs). Assembly with TARP γ8 alters the biophysical properties of the receptor, producing resensitization currents in the continued presence of glutamate. Using single-channel recordings, we show that under resensitizing conditions, GluA2 AMPA receptors primarily transition to higher conductance levels, similar to activation of the receptors in the presence of cyclothiazide, which stabilizes the open state. To study the conformation associated with these states, we have used single-molecule FRET and show that this high-conductance state exhibits tighter coupling between subunits in the extracellular parts of the receptor. Furthermore, the dwell times for the transition from the tightly coupled state to the decoupled states correlate to longer open durations of the channels, thus correlating conformation and function at the single-molecule level.

PMID:
31748249
PMCID:
PMC7034100
[Available on 2020-07-06]
DOI:
10.1085/jgp.201912451

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center