Mechanism of Ca²⁺/calmodulin-dependent kinase II regulation of AMPA receptor gating

TY - JOUR

T1 - Mechanism of Ca2+/calmodulin-dependent kinase II regulation of AMPA receptor gating

AU - Kristensen, Anders Skov

AU - Jenkins, Meagan A

AU - Banke, Tue G

AU - Schousboe, Arne

AU - Makino, Yuichi

AU - Johnson, Richard C

AU - Huganir, Richard

AU - Traynelis, Stephen F

PY - 2011/6/1

Y1 - 2011/6/1

N2 - The function, trafficking and synaptic signaling of AMPA receptors are tightly regulated by phosphorylation. Ca(2+)/calmodulin-dependent kinase II (CaMKII) phosphorylates the GluA1 AMPA receptor subunit at Ser831 to increase single-channel conductance. We show that CaMKII increases the conductance of native heteromeric AMPA receptors in mouse hippocampal neurons through phosphorylation of Ser831. In addition, co-expression of transmembrane AMPA receptor regulatory proteins (TARPs) with recombinant receptors is required for phospho-Ser831 to increase conductance of heteromeric GluA1-GluA2 receptors. Finally, phosphorylation of Ser831 increases the efficiency with which each subunit can activate, independent of agonist efficacy, thereby increasing the likelihood that more receptor subunits will be simultaneously activated during gating. This underlies the observation that phospho-Ser831 increases the frequency of openings to larger conductances rather than altering unitary conductance. Together, these findings suggest that CaMKII phosphorylation of GluA1-Ser831 decreases the activation energy for an intrasubunit conformational change that regulates the conductance of the receptor when the channel pore opens.

AB - The function, trafficking and synaptic signaling of AMPA receptors are tightly regulated by phosphorylation. Ca(2+)/calmodulin-dependent kinase II (CaMKII) phosphorylates the GluA1 AMPA receptor subunit at Ser831 to increase single-channel conductance. We show that CaMKII increases the conductance of native heteromeric AMPA receptors in mouse hippocampal neurons through phosphorylation of Ser831. In addition, co-expression of transmembrane AMPA receptor regulatory proteins (TARPs) with recombinant receptors is required for phospho-Ser831 to increase conductance of heteromeric GluA1-GluA2 receptors. Finally, phosphorylation of Ser831 increases the efficiency with which each subunit can activate, independent of agonist efficacy, thereby increasing the likelihood that more receptor subunits will be simultaneously activated during gating. This underlies the observation that phospho-Ser831 increases the frequency of openings to larger conductances rather than altering unitary conductance. Together, these findings suggest that CaMKII phosphorylation of GluA1-Ser831 decreases the activation energy for an intrasubunit conformational change that regulates the conductance of the receptor when the channel pore opens.

KW - Former Faculty of Pharmaceutical Sciences

U2 - 10.1038/nn.2804

DO - 10.1038/nn.2804

M3 - Journal article

C2 - 21516102

SN - 1097-6256

VL - 14

SP - 727

EP - 735

JO - Nature Neuroscience

JF - Nature Neuroscience

IS - 6

ER -