Zipper-interacting protein kinase interacts with human cell division cycle 14A phosphatase.

Zipper-interacting protein kinase (ZIPK) is a novel serine/threonine protein kinase and a member of a large family of protein kinases, known as the death-associated protein kinases. However, the function of ZIPK has yet to be fully elucidated, as few physiological substrates have currently been identified. In the present study, a yeast two-hybrid screen was used and the human cell division cycle 14A (HsCdc14A) phosphatase was identified as a novel ZIPK binding protein. To the best of our knowledge, this is the first study to report the interaction between these proteins. The interaction between ZIPK and HsCdc14A was confirmed by in vitro experiments. In addition, ZIPK-mediated phosphorylation was shown to activate the phosphatase activity of HsCdc14A. These findings indicated that ZIPK may also be involved in the regulation of the cell cycle in human cells, by interacting with HsCdc14A.