Skp2 regulates DNA damage repair and apoptosis via interaction with Ku70

Abstract Purpose Skp2, an oncoprotein, regulates tumor proliferation, invasion and metastasis. Ku70 is a critical component of the non-homologous end-joining (NHEJ) process. Both Skp2 and Ku70 are positively associated in multiple cancers. However, there is no report about the relationship between Skp2 and Ku70 proteins. Methods In this study, we carried out Bioinformatics and molecular biological methods to investigate the relationship between Skp2 and Ku70 proteins. Results We first observed Skp2 and Ku70 mRNAs were significantly increased in cervical cancer tissues. And we identified Ku70 as a Skp2-binding protein and the binding site located in the C–terminal of Ku70 protein. We further found that Skp2 knockdown decreased the Ku70 protein level in cells, and increase the cellular apoptosis and DNA damage, suggesting Skp2 mediates the Ku70 protein stability and function via post-translational modification. Conclusion The direct interaction between Skp2 and Ku70 proteins mediates the DNA damage repair and cellular apoptosis by regulating Ku70 stability and function via post-translational modification. The molecular mechanisms how Skp2 stabilize Ku70 would be clarified in our following research work.