Figure 5.

Minor satellite RNA potentiate endogenous Aurora B kinase activity. (A) Kinase activity of immunoprecipitated Aurora B in presence of increasing amounts (10, 20, 50 pmol) of in vitro transcribed minor satellite RNA (minsat). Control reactions were performed in presence of increasing amounts (10, 20, 50 pmol) of in vitro transcribed β-tubulin RNA (β-tub) or in absence of histones (No hist). (B) Kinase activity of endogenous Aurora B after RNaseA treatment and rescue assay with addition of in vitro transcribed minor satellite RNA (50, 75 pmol), in presence of RNase inhibitors. As a negative control, the same amount of in vitro transcribed β-tubulin RNA (50, 75 pmol) was used in the rescue assay. Specific histone H3 phosphate incorporation (³²P-H3) was quantified by phosphorimager, Aurora B protein levels were determined by western blotting and histones visualized by Ponceau red staining.