Zfp322a regulates mouse ES cell pluripotency and enhances reprogramming efficiency [ChIP-Seq]
Embryonic stem (ES) cells derived from the inner cell mass (ICM) of blastocysts are characterised by their ability to self-renew and their potential to differentiate into many different cell types. Recent studies have shown that zinc finger proteins are crucial for maintaining pluripotent ES cells. Mouse zinc finger protein 322a (Zfp322a) is expressed in the ICM of early mouse embryos. However, little is known regarding the role of Zfp322a in the pluripotentcy maintenance of ES cells. Here, we report that Zfp322a is required for ES cell identity since depletion of Zfp322a directs ES cells towards differentiation. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays revealed that Zfp322a binds to Oct4 and Nanog promoters and regulates their transcription. These data along with the results obtained from our ChIP-seq experiment showed that Zfp322a is an essential component of the ES cell transcription regulatory network. Targets which are directly regulated by Zfp322a were identified by correlating the gene expression profile of Zfp322a RNAi-treated ES cells with the ChIP-seq results. These experiments revealed that Zfp322a inhibits ES cell differentiation by suppressing MAPK pathway. Additionally, Zfp322a is found to be a novel reprogramming factor that can replace Sox2 in the classical Yamanaka’s factors (OSKM). It can be even used in combination with Yamanaka’s factors and that addition leads to a higher reprogramming efficiency and to acceleration of the onset of the reprogramming process. Together, our results demonstrate that Zfp322a is a novel essential component of the transcription factor network which maintains the identity of ES cells. Overall design: E14 mES cells were immunoprecipitated with Zfp322a antibody or IgG from rabbit.