FRM-3/FARP bridges α7-like N-AChRs with LIN-2/CASK and SDN-1. (A) Confocal detection and quantification of ACR-16-wrmScarlet in control, frm-3(0) and frm-3(0) animals expressing full length FRM-3A-GFP, FERM-FA-GFP or FERM-GFP truncations driven by the muscle-specific Pmyo-3 promoter. (B) Confocal detection and fluorescent profiles of GABA_ARs (RFP-UNC-49) and FRM-3B-GFP in control and sdn-1(0) animals expressing frm-3b-gfp driven by the muscle-specific promoter Pmyo-3. (C) Quantification of FRM-3B-GFP fluorescence level. (D) Pearson’s correlation coefficient between FRM-3B-GFP and GABA bouton. (E) Confocal detection and quantification of mNG-SDN-1 full length or lacking the KKDEGS motif (ΔKKDEGS). (F) Confocal detection and quantification of FRM-3B-GFP in control and sdn-1(ΔEYFA) animals expressing frm-3b-gfp under the control of the muscle-specific promoter Pmyo-3. (G) Confocal detection of ACR-16-wrmScarlet in control or in mNG-SDN-1 knock-in animals lacking the KKDEGS motif. (H) GST pull-down analysis of the binding between HA-tagged FRM-3B and SDN-1_ICD, PDZ-binding motif deletion (SDN-1_ICDΔEYFA), C1 motif deletion (SDN-1ICDΔKKDEGS) by immunoblotting using anti-HA antibody. The same membrane was stained by Ponceau red to show GST expression. Molecular weights (Mw) are shown on the right. (I) GST pull-down analysis of ACR-16 TM3-TM4 cytosolic loop binding with HA tagged LIN-2B or FERM-FA domain of FRM-3 by immunoblotting using anti-HA antibody. The same membrane was probed by anti-GST antibody to show GST expression. Molecular weight (Mw) is shown on the right. Scale bars, 10 µm.