Rat-brain membranes (RBM) and cell lysates from tsA201 cells transiently expressing KCNQ2/pECFP-N1 were prepared as described previously (Foster et al., 2012 (link)). RBM and cell lysates were solubilised in 1% Triton X-100 lysis buffer and incubated overnight with a rabbit anti-KCNQ2 (AB22897, Abcam; 1-2 μg/ml) or a mouse anti-KCNQ2 (N26A/23, NeuroMab, Davis, CA; 1-2 μg/ml), and rabbit anti-GFP polyclonal antibodies (A6455, Life technologies; 1-2 μl/ml), respectively. Antigen-antibody complexes were then incubated with protein G beads (GE Healthcare) for four h at 4 °C. After six washes, bound proteins were eluted in SDS sample buffer at 95 °C for three min. Eluted proteins were size fractionated on SDS-PAGE gels, and visualised by a colloidal blue staining (Invitrogen). For immunoblot with GST-Kv7.2C, purified proteins were separated on SDS-PAGE gels and transferred to polyvinylidene fluoride membranes (Waters, Milford, MA), which were then immunostained with anti-KCNQ2 (N26A/23, 0.22 μg/ml) antibody.