WNK-dependent phosphorylation of gephyrin tunes GABA A receptors at inhibitory synapses and modulates anxiety behavior
Abstract
Summary The role of the chloride-sensitive kinase WNK1 and its effector SPAK in the brain remains poorly understood. Here, we identify a regulatory mechanism involving WNK signaling that directly controls the synaptic diffusion and clustering, as well as the membrane stability and endocytosis of inhibitory GABA A receptors (GABA A Rs). We show that activation of WNK signaling stabilizes GABA A Rs at inhibitory synapses, while inhibition enhances receptor internalization. This regulation depends on the phosphorylation state of two previously uncharacterized residues in the central linker region of the gephyrin scaffold protein. Modulating WNK activity alters neuronal activity and the kinetics of GABAergic currents. In vivo , expression of a phospho-mimetic form of gephyrin at WNK-targeted sites produces anxiolytic effects. By orchestrating the recruitment of GABA A Rs at inhibitory synapses, the WNK pathway emerges as a master regulator of GABAergic transmission and establishes chloride as a bona fide second messenger in inhibitory synaptic signaling. Significance Synaptic transmission relies on signaling pathways that control how neurotransmitter receptors move and stabilize at synapses. Many of these pathways use calcium as a second messenger. In contrast, how chloride might regulate synapses has remained unclear. In this study, we identify a chloride-sensitive pathway involving the WNK1 kinase and its partner SPAK, which controls the movement and stability of inhibitory GABA A receptors at synapses. This occurs through the phosphorylation of gephyrin, a key scaffolding protein, at two newly identified sites. Our results show that intracellular chloride can act as a second messenger, reshaping inhibitory synapses and altering behavior in mice, including reducing anxiety-like responses.
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BibTeX
@article{merlaud2026wnkdependent,
title = {{WNK-dependent phosphorylation of gephyrin tunes GABA A receptors at inhibitory synapses and modulates anxiety behavior}},
author = {Zaha Merlaud and Celia Delhaye and Margarida Nabais and Erwan Pol and Tânia Lima and Yann Verdier and Zahra Imani and Marion Russeau and Nalia Samba and Maelys Tostain and Juliette Gouhier and Romane Rahir and Joëlle Vinh and Corentin Le Magueresse and Marika Nosten-Bertrand and Sabine Lévi},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
year = {2026},
month = aug,
doi = {10.1073/pnas.2612761123},
url = {https://hal.science/hal-05733696v1},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - WNK-dependent phosphorylation of gephyrin tunes GABA A receptors at inhibitory synapses and modulates anxiety behavior
AU - Zaha Merlaud
AU - Celia Delhaye
AU - Margarida Nabais
AU - Erwan Pol
AU - Tânia Lima
AU - Yann Verdier
AU - Zahra Imani
AU - Marion Russeau
AU - Nalia Samba
AU - Maelys Tostain
AU - Juliette Gouhier
AU - Romane Rahir
AU - Joëlle Vinh
AU - Corentin Le Magueresse
AU - Marika Nosten-Bertrand
AU - Sabine Lévi
PY - 2026
DA - 2026/08/25
JO - Proceedings of the National Academy of Sciences of the United States of America
DO - 10.1073/pnas.2612761123
UR - https://hal.science/hal-05733696v1
AB - Summary The role of the chloride-sensitive kinase WNK1 and its effector SPAK in the brain remains poorly understood. Here, we identify a regulatory mechanism involving WNK signaling that directly controls the synaptic diffusion and clustering, as well as the membrane stability and endocytosis of inhibitory GABA A receptors (GABA A Rs). We show that activation of WNK signaling stabilizes GABA A Rs at inhibitory synapses, while inhibition enhances receptor internalization. This regulation depends on the phosphorylation state of two previously uncharacterized residues in the central linker region of the gephyrin scaffold protein. Modulating WNK activity alters neuronal activity and the kinetics of GABAergic currents. In vivo , expression of a phospho-mimetic form of gephyrin at WNK-targeted sites produces anxiolytic effects. By orchestrating the recruitment of GABA A Rs at inhibitory synapses, the WNK pathway emerges as a master regulator of GABAergic transmission and establishes chloride as a bona fide second messenger in inhibitory synaptic signaling. Significance Synaptic transmission relies on signaling pathways that control how neurotransmitter receptors move and stabilize at synapses. Many of these pathways use calcium as a second messenger. In contrast, how chloride might regulate synapses has remained unclear. In this study, we identify a chloride-sensitive pathway involving the WNK1 kinase and its partner SPAK, which controls the movement and stability of inhibitory GABA A receptors at synapses. This occurs through the phosphorylation of gephyrin, a key scaffolding protein, at two newly identified sites. Our results show that intracellular chloride can act as a second messenger, reshaping inhibitory synapses and altering behavior in mice, including reducing anxiety-like responses.
SN - 0027-8424
SN - 1091-6490
ER -