Figure 4.

α-Syntrophin induced ARMS clustering in a PDZ domain–dependent manner. (A) Immunostaining of COS7 cells transfected with either ARMS, HA–α-syntrophin, or both ARMS and HA–α-syntrophin. α-Syntrophin (SYN1351 antibody staining, red) induced ARMS clustering (ARMS antibody staining, green) in cotransfected cells, whereas α-syntrophin itself remained diffused. (B) Mutations in either α-syntrophin PDZ domain (HA-α-syn mPDZ) or ARMS COOH terminus (ARMS ΔSIL and ARMS S1713D) abolished ARMS cluster formation. The immunostaining was performed as stated in A. (C) PSD-95 did not induce ARMS clustering when they were coexpressed in COS7 cells. Bars, 10 μm.