SAP97 promotes the stability of Nax channels at the plasma membrane

Abstract

Nax is a sodium-level sensor for body fluids expressed in the circumventricular organs in the brain. Nax has a putative PSD-95/Disc-large/ZO-1 (PDZ)-binding motif at the carboxyl (C)-terminus. Here we found that several PDZ proteins bind to Nax by PDZ-array overlay assay. Among them, synapse-associated protein 97 (SAP97/DLG1) was coexpressed with Nax in the subfornical organ. In C6 glioblastoma cells, destruction of the PDZ-binding motif of Nax or depletion of SAP97 resulted in a decrease in cell-surface Nax, which was attenuated with inhibitors of endocytosis. These results indicate that SAP97 contributes to the stabilization of Nax channels at the plasma membrane. Structured summary of protein interactionsNaxphysically interacts with SAP97 by anti tag coimmunoprecipitation (View interaction) CNRasGEFbinds to Nax by protein array (View interaction) Nax and SAP97colocalize by fluorescence microscopy (View interaction) GIPC1binds to Nax by protein array (View interaction) ZO-1binds to Nax by protein array (View interaction) SAP97binds to Nax by protein array (View interaction) Densin-180binds to Nax by protein array (View interaction) Beta-1-syntrophinbinds to Nax by protein array (View interaction) ERBINbinds to Nax by protein array (View interaction) Naxphysically interacts with SAP97 by pull down (View interaction) Lnx1binds to Nax by protein array (View interaction) nNOSbinds to Nax by protein array (View interaction)