WWC2 modulates GABA A -receptor-mediated synaptic transmission, revealing class-specific mechanisms of synapse regulation by WWC family proteins

• Published in: Cell reports (Cambridge) 2024-10, Vol.43 (10), p.114841
• Main Authors: Dunham, Thomas L, Wilkerson, Julia R, Johnson, Richard C, Huganir, Richard L, Volk, Lenora J
• Format: Article
• Language: English
• ISSN: 2211-1247

The WW and C2 domain-containing protein (WWC2) is implicated in several neurological disorders. Here, we demonstrate that WWC2 interacts with inhibitory, but not excitatory, postsynaptic scaffolds, consistent with prior proteomic identification of WWC2 as a putative component of the inhibitory postsynaptic density. Using mice lacking WWC2 expression in excitatory forebrain neurons, we show that WWC2 suppresses γ-aminobutyric acid type-A receptor (GABA R) incorporation into the plasma membrane and regulates HAP1 and GRIP1, which form a complex promoting GABA R recycling to the membrane. Inhibitory synaptic transmission is increased in CA1 pyramidal cells lacking WWC2. Furthermore, unlike the WWC2 homolog KIBRA (kidney/brain protein; WWC1), a key regulator of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) trafficking at excitatory synapses, the deletion of WWC2 does not affect synaptic AMPAR expression. In contrast, loss of KIBRA does not affect GABA R membrane expression. These data reveal synapse class-selective functions for WWC proteins as regulators of ionotropic neurotransmitter receptors and provide insight into mechanisms regulating GABA R membrane expression.