GFP and TAP-tag Immunoprecipitation

In vivo interactions studies were carried out following the protocols published previously (18 (link),27 (link)). For immunoprecipitation of GFP-tagged proteins, 10 μl slurry of GFP-Trap_A beads (Chromotek) and for TAP-tagged proteins, 20 μl slurry of IgG-Sepharaose beads (GE Healthcare) were used per reaction and incubated with 200 (high abundant proteins) and up to 2000 μl (for low abundant proteins) of the clarified lysate for 3 h rotating at 4°C. If indicated, the samples were treated with 0.2 mg/ml RNase A (AppliChem) for additional 30 min at 4°C. Finally, the eluted proteins were separated on 10% SDS-polyacrylamide gels and analysed by western blotting.