Complementary Activity of ETV5, RBPJ, and TCF3 Drives Formative Transition from Naive Pluripotency

Summary

The gene regulatory network (GRN) of naive mouse embryonic stem cells (ESCs) must be reconfigured to enable lineage commitment. TCF3 sanctions rewiring by suppressing components of the ESC transcription factor circuitry. However, TCF3 depletion only delays and does not prevent transition to formative pluripotency. Here, we delineate additional contributions of the ETS-family transcription factor ETV5 and the repressor RBPJ. In response to ERK signaling, ETV5 switches activity from supporting self-renewal and undergoes genome relocation linked to commissioning of enhancers activated in formative epiblast. Independent upregulation of RBPJ prevents re-expression of potent naive factors, TBX3 and NANOG, to secure exit from the naive state. Triple deletion of Etv5, Rbpj, and Tcf3 disables ESCs, such that they remain largely undifferentiated and locked in self-renewal, even in the presence of differentiation stimuli. Thus, genetic elimination of three complementary drivers of network transition stalls developmental progression, emulating environmental insulation by small-molecule inhibitors.

Graphical Abstract

Highlights

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  Downstream of pErk, ETV5 initiates GRN handover during ESC transition

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  RBPJ enforces naive pluripotency exit by preventing re-expression of NANOG or TBX3

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  ETV5 relocates to commission formative pluripotency enhancers

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  ESCs lacking TCF3, ETV5, and RBPJ are trapped in a naive but nullipotent condition

Abstract

Smith, Kalkan, and colleagues report that the gene regulatory network in naive mouse embryonic stem cells is reconfigured to enable lineage commitment by combined action of two repressors, TCF3 and RBPJ, that dissolve and extinguish, respectively, the naive network and an activator, ETV5, that switches activity from supporting self-renewal and undergoes genome relocation linked to commissioning of enhancers in formative epiblast.