U2OS cells were transfected with empty pcDNA3 vector (pcDNA3) or expression vectors encoding Flag-DDX5 WT (1-614) or truncated Flag-DDX5 proteins (60-614; 1-554; 1-435). WCE of the transfected cells (left panel) were Western blotted with anti-Flag and anti-XRN2 antibodies to confirm equivalent expression. The transfected cells were lysed and anti-Flag immunoprecipitations (right panel) performed for the presence of co-immunoprecipitating endogenous XRN2 by Western blotting with anti-XRN2 antibodies. M denotes molecular mass markers in kDa. 