EMBRYONIC STEM CELLS/INDUCED PLURIPOTENT STEM CELLS Zfp281 Functions as a Transcriptional Repressor for Pluripotency of Mouse Embryonic Stem Cells

Embryonic stem cells (ESCs) derived from preimplanta-tion blastocysts have unique self-renewal and multilineage differentiation properties that are controlled by key com-ponents of a core regulatory network including Oct4, Sox2, and Nanog. Understanding molecular underpinnings of these properties requires identification and characteri-zation of additional factors that act in conjunction with these key factors in ESCs. We have previously identified Zfp281, a Krüppel-like zinc finger transcription factor, as an interaction partner of Nanog. We now present detailed functional analyses of Zfp281 using a genetically ablated null allele in mouse ESCs. Our data show that while Zfp281 is dispensable for establishment and maintenance of ESCs, it is required for their proper differentiation in vitro. We performed microarray profiling in combination with previously published datasets of Zfp281 global target gene occupancy and found that Zfp281 mainly functions as a repressor to restrict expression of many stem cell plu-ripotency genes. In particular, we demonstrated that dele-tion of Zfp281 resulted in upregulation of Nanog at both the transcript and protein levels with concomitant com-promised differentiation of ESCs during embryoid body culture. Chromatin immunoprecipitation experiments demonstrated that Zfp281 is required for Nanog binding to its own promoter, suggesting that Nanog-associated re-pressive complex(es) involving Zfp281 may fine-tune Nanog expression for pluripotency of ESCs. STEM CELLS 2011;29:1705–1716 Disclosure of potential conflicts of interest is found at the end of this article