Figure 1. Enhanced green fluorescent protein (EGFP)‐tagged SF2/ASF and SRp30c constructs were expressed in HEK293 cells together with HA‐PP1, and immunoprecipitated with anti‐GFP antibodies. WT: RVEF (PP1 binding site); mt: RVEF changed to RATA (destroying the PP1‐binding site). The presence of HA‐PP1 in the immunoprecipitates was determined by Western blotting. Load: Western blot using material from the cell lysates.

Figure 2. Phosphorylation‐mediated interaction of recombinant rSLM1 protein with its partners. rSLM‐1 is an RNA‐binding protein involved in transducing cellular signals to the spliceosome [ 5]. Recombinant rSLM1–GST‐tagged protein was incubated with several in vitro‐translated proteins. The load of in vitro‐translated protein is marked as I (1/10 of the total volume), “n” indicates binding of the in vitro‐translated proteins to recombinant rSLM1‐GSTtag protein, and “p” the binding of phosphorylated recombinant protein to sSLM‐1. The phosphorylation was carried out in vitro using c‐abl. The percentage values indicate the binding affinity.