ZFP560 facilitates KAP1-dependent chromatin repression to regulate exit from totipotency

Abstract KRAB zinc finger proteins (KRAB-ZFPs) are the most abundant transcriptional regulators and epigenetic repressors in mammals, contributing to the silencing of transposable elements (TEs) during embryonic development. However, the early effectors of the KRAB-ZFP family during embryonic development and cell state transition remain largely unexplored. Here, we demonstrate that zinc finger protein 560 (ZFP560) is involved in the regulation of early embryonic development and the transition from totipotency in mice. ZFP560 safeguards heterochromatin structure by targeting KAP1 to facilitate the exit of totipotency network. Its deficiency disrupted heterochromatin formation, significantly halted the transition from totipotency to pluripotency. Correspondingly, the overexpression of Zfp560 promoted the exit from MERVL positive state, as well as 2C transcription factors, by recruiting KAP1 through KRAB domain to reduce the chromatin accessibility. Together, we identify ZFP560, a highly expressed 2-cell embryo specific KRAB-ZFP transcription factor, as a novel mediator facilitating the exit from totipotency, providing new insights into the epigenetic regulation of early embryonic development.