The ZFP57 imprinting factor and epigenetic control: further clues stemming from expression profiling, ChIP seq and in vitro-induced differentiation

Epigenetic marks are key to embryogenesis and are linked to the regulation of pluripotency, cell fate and cellular identity. Extensive epigenetic reprogramming occurs at early embryos stages and exceptions are the parent of origin-specific signatures at Imprinting Control Regions (ICRs) driving regulation of imprinted genes. ZFP57 was shown to be required for the maintenance of DNA methylation at ICRs in embryos and of both DNA methylation and histone H3 modification in embrional stem cells (ES). ZFP57 associates with KAP1, a recruiter of chromatin modifiers including the H3 methyltransferase SETDB1 and HP1, thus promoting H3 K9-trimethylation and chromoproteins assembly at targeted sites. ChIP seq profiling in ES cells of endogenous ZFP7 and associated factors shows assembly at hundreds regions in addition to imprinted loci and we will report on ongoing studies that integrate expression profiling, genome-wide occupancy, the status of selected targets and in vitro cell differentiation that suggest a wider role for ZFP57 in shaping the pluripotent epigenome and provide further clues for its involvement in development and cell fate.