Fig. 8. A model for GLR-1/GLR-2 subunit association and localization. GLR-1 and GLR-2 subunits are represented by black and gray half-pentagons, respectively. Their carboxy-terminal tail sequences are shown as rectangles projecting into the cytosol. An as yet unknown PDZ-domain protein and LIN-10, which facilitate channel localization, are shown as half-circles and trapezoids, respectively. GLR-1 and GLR-2 can form homomeric channels or heteromeric channels, and the presence one or more carboxy-terminal tail sequences per channel can allow for channel localization. Both the PDZ-binding motif and sequences outside of this motif are required for efficient localization, suggesting that an unknown PDZ domain protein and perhaps LIN-10 might cooperate to localize these channels. Channels that lack the tail sequences cannot interact with these proteins, and therefore fail to become localized.