Yap is regulated by phosphorylation at the G2/M transition

Yap is a small protein that acts as a co-activator of transcription. It has been shown to interact with many and diverse transcription factors and as a result of these promiscuous interactions, Yap has been described to have a role in many cellular events, including apoptosis, proliferation, and differentiation. For this reason, it is described to have a role both in tumor suppression and transformation. However, the function of Yap in the regulation of the cell cycle has not been investigated so far. Here we demonstrate that Yap is phosphorylated at the G2/M, both in physiologic mitotic cells and in cells arrested in mitosis by microtubules-targeting drugs. We show that Yap is not recruited onto the chromatin during mitosis and does not localize to any mitotic organelles. In addition, we have noticed that de-phosphorylation of Yap occurs before the entry into G1. These data give an indication that Yap may have a role in the exit from mitosis, and place a solid foundation for characterizing the function(s) of Yap during this event.