Recovery from desensitization in GluA2 AMPA receptors is affected by a single mutation in the N-terminal domain interface
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Recovery from desensitization in GluA2 AMPA receptors is affected by a single mutation in the N-terminal domain interface. / Larsen, Andreas Haahr; Perozzo, Amanda M.; Biggin, Philip C.; Bowie, Derek; Kastrup, Jette Sandholm.
In: Journal of Biological Chemistry, Vol. 300, No. 3, 105717, 2024.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Recovery from desensitization in GluA2 AMPA receptors is affected by a single mutation in the N-terminal domain interface
AU - Larsen, Andreas Haahr
AU - Perozzo, Amanda M.
AU - Biggin, Philip C.
AU - Bowie, Derek
AU - Kastrup, Jette Sandholm
N1 - Publisher Copyright: © 2024
PY - 2024
Y1 - 2024
N2 - AMPA-type ionotropic glutamate receptors (AMPARs) are central to various neurological processes, including memory and learning. They assemble as homo- or heterotetramers of GluA1, GluA2, GluA3, and GluA4 subunits, each consisting of an N-terminal domain (NTD), a ligand-binding domain, a transmembrane domain, and a C-terminal domain. While AMPAR gating is primarily controlled by reconfiguration in the ligand-binding domain layer, our study focuses on the NTDs, which also influence gating, yet the underlying mechanism remains enigmatic. In this investigation, we employ molecular dynamics simulations to evaluate the NTD interface strength in GluA1, GluA2, and NTD mutants GluA2-H229N and GluA1-N222H. Our findings reveal that GluA1 has a significantly weaker NTD interface than GluA2. The NTD interface of GluA2 can be weakened by a single point mutation in the NTD dimer-of-dimer interface, namely H229N, which renders GluA2 more GluA1-like. Electrophysiology recordings demonstrate that this mutation also leads to slower recovery from desensitization. Moreover, we observe that lowering the pH induces more splayed NTD states and enhances desensitization in GluA2. We hypothesized that H229 was responsible for this pH sensitivity; however, GluA2-H229N was also affected by pH, meaning that H229 is not solely responsible and that protons exert their effect across multiple domains of the AMPAR. In summary, our work unveils an allosteric connection between the NTD interface strength and AMPAR desensitization.
AB - AMPA-type ionotropic glutamate receptors (AMPARs) are central to various neurological processes, including memory and learning. They assemble as homo- or heterotetramers of GluA1, GluA2, GluA3, and GluA4 subunits, each consisting of an N-terminal domain (NTD), a ligand-binding domain, a transmembrane domain, and a C-terminal domain. While AMPAR gating is primarily controlled by reconfiguration in the ligand-binding domain layer, our study focuses on the NTDs, which also influence gating, yet the underlying mechanism remains enigmatic. In this investigation, we employ molecular dynamics simulations to evaluate the NTD interface strength in GluA1, GluA2, and NTD mutants GluA2-H229N and GluA1-N222H. Our findings reveal that GluA1 has a significantly weaker NTD interface than GluA2. The NTD interface of GluA2 can be weakened by a single point mutation in the NTD dimer-of-dimer interface, namely H229N, which renders GluA2 more GluA1-like. Electrophysiology recordings demonstrate that this mutation also leads to slower recovery from desensitization. Moreover, we observe that lowering the pH induces more splayed NTD states and enhances desensitization in GluA2. We hypothesized that H229 was responsible for this pH sensitivity; however, GluA2-H229N was also affected by pH, meaning that H229 is not solely responsible and that protons exert their effect across multiple domains of the AMPAR. In summary, our work unveils an allosteric connection between the NTD interface strength and AMPAR desensitization.
KW - AMPAR
KW - electrophysiology
KW - GluA1
KW - GluA2
KW - MD
KW - metadynamics
KW - molecular dynamics
KW - patch clamp
KW - potential of mean force
KW - SANS
KW - small-angle neutron scattering
U2 - 10.1016/j.jbc.2024.105717
DO - 10.1016/j.jbc.2024.105717
M3 - Journal article
C2 - 38311178
AN - SCOPUS:85186599820
VL - 300
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 3
M1 - 105717
ER -
ID: 385260002