(A) Schematic of two-color SiMPull experiments. Fresh HEK293T cell lysate expressing HA-SNAP-mGluR2 with CLIP-mGluR1, 2, 3, 4, or 7 is added to the polyethylene glycol (PEG) passivated cover glass containing biotinylated anti-HA antibody. SNAP and CLIP tags are labeled with BG-LD655 and BC-DY547, respectively.
(B and C) Representative SiMPull images of HA-SNAP-mGluR2 with CLIP-mGluR2 (B) or CLIP-mGluR3 (C).
(D) Quantification of pull-down via HA-SNAP-mGluR2 normalized to the homodimer condition of HA-SNAP-mGluR2 with CLIP-mGluR2. The asterisk indicates statistical significance (unpaired t test versus mGluR2/2: p = 0.002 for mGluR2/1; p = 0.04 for mGluR2/3, p = 0.05 for mGluR2/7). Relative dimerization strength is shown in a schematic (right). Data are represented as mean ± SEM. Scale bars, 10 µm.