Identification of Yap-interacting proteins in Xenopus egg extracts by co-immunoprecipitation coupled to LC/MS/MS

Yap (Yes-associated protein 1) is a downstream effector of the Hippo signaling pathway and known as a transcriptional co-activator. We previously identified Yap1 as a novel factor implicated in the control of the temporal DNA replication program in Xenopus retinal stem cells. However, whether Yap is directly involved in DNA replication dynamics and whether it could regulate DNA replication during early embryonic divisions in the absence of transcription remained to be investigated. We now found that in Yap depleted Xenopus laevis egg extracts the activation of replication origins was increased. In order to understand by which mechanism Yap could regulate the initiation of DNA replication in the absence of transcription we searched for new interacting factors. We immunoprecipitated Yap from Xenopus laevis egg extracts using anti-Yap, compared to control antibodies, and analyzed co-immunoprecipitating proteins by nanoLC/MS/MS.