Research Article

Interaction and Correlation of Pin1 with Aurora B Expression in Human Colorectal Carcinoma Cells

Author: Lixin Jiang and Jian Chen

Background: The Peptidyl-prolylisomerase (PPIase) Pin1 and Aurora B kinase are two important proteins involved in cell cycle progression. They are frequently over expressed or amplified in human tumors and are regarded as new diagnostic and therapeutic targets. However, to the best of our knowledge, there is currently no published report about the interaction between Pin1 and Aurora B. Methods: The interaction between Pin1 and Aurora B in human colorectal cancer cells HCT116 was investigated by Glutathione S-Transferase (GST) pull-down and immunoprecipitation assays. Their colocalization during mitosis was confirmed by immunofluorescence staining. Results: We showed binding betweenPin1 and Aurora B in vitro. Over expression of Pin1 resulted in decreased levels of the Aurora B protein, whereas over expression of Aurora B led to increased expression of Pin1. During mitosis, from the Gap phase to cytokinesis, Aurora B and Pin1 colocalized in the cytoplasm or on the chromosome. Conclusion: Aurora B could be a substrate for Pin1through the recognition of the pT35 and pT64 sites of Aurora B. Prolyl isomerization by Pin1 may accelerate Aurora B turnover.