β-Catenin and Associated Proteins Regulate Lineage Differentiation in Ground State Mouse Embryonic Stem Cells

Summary Mouse embryonic stem cells (ESCs) cultured in defined medium resemble the pre-implantation epiblast in the ground state, with full developmental capacity including the germline. β-Catenin is required to maintain ground state pluripotency in mouse ESCs, but its exact role is controversial. Here, we reveal a Tcf3-independent role of β-catenin in restraining germline and somatic lineage differentiation genes. We show that β-catenin binds target genes with E2F6 and forms a complex with E2F6 and HMGA2 or E2F6 and HP1γ. Our data indicate that these complexes help β-catenin restrain and fine-tune germ cell and neural developmental potential. Overall, our data reveal a previously unappreciated role of β-catenin in preserving lineage differentiation integrity in ground state ESCs.
Highlights • β-Catenin depletion irreversibly compromised lineage development of ground state ESCs • TCF3-independent role of β-catenin in determining lineage differentiation potential • E2F6, HP1γ, and HMGA2 are β-catenin interaction partners and co-bound to target genes • β-Catenin and protein partners fine-tune germline and neural development potential
In this article, Tao and colleagues show that β-catenin functions beyond derepressing TCF3 targeted pluripotency network in ESCs. β-Catenin physically interacts with protein partners, including transcription factor and chromatin modulators. Together, they preserve the integrity of lineage differentiation of ground state ESCs by restraining and fine-tuning their germline and neural development potential.