Phosphorylation sites that influences the RNA-binding activity of Papi

We conducted UV cross-linking immunoprecipitation (CLIP) with and without phosphatase inhibitor and compared the outcome. The topmost band on the western blots appeared more prominent with the inhibitor. The RNA-binding activity of the band was also stronger with the inhibitor. We isolated the band and subjected to LC-MS/MS to identify the phosphorylated residues.