Project description:RAS proteins are key regulators of growth factor signaling. Here we show that deletion of all RAS genes in mouse embryonic stem cells (mES) leads to an overall reduction in protein translation, limits their long-term proliferative capacity and incapacitates them to differentiate. Deletion of ERF, a transcriptional repressor of the ETS family, rescues proliferation and differentiation of RAS-deficient mES cells and allows the development of teratomas lacking RAS genes. Upon RAS deletion, ERF translocates to the nucleus where it binds to multiple enhancers of key RAS targets suppressing their expression. We also reveal recurrent losses of ERF in cancer and show that ERF deficiency increases the resistance of cancer cells to pharmacological inhibition of the RAS pathway. In summary, we here reveal a central role for ERF in coordinating RAS signaling in pluripotent cells, and identify a synthetic viable interaction that bypasses the requirement for RAS proteins in mammalian cells.
Project description:RAS proteins are key regulators of growth factor signaling. Here we show that deletion of all RAS genes in mouse embryonic stem cells (mES) leads to an overall reduction in protein translation, limits their long-term proliferative capacity and incapacitates them to differentiate. Deletion of ERF, a transcriptional repressor of the ETS family, rescues proliferation and differentiation of RAS-deficient mES cells and allows the development of teratomas lacking RAS genes. Upon RAS deletion, ERF translocates to the nucleus where it binds to multiple enhancers of key RAS targets suppressing their expression. We also reveal recurrent losses of ERF in cancer and show that ERF deficiency increases the resistance of cancer cells to pharmacological inhibition of the RAS pathway. In summary, we here reveal a central role for ERF in coordinating RAS signaling in pluripotent cells, and identify a synthetic viable interaction that bypasses the requirement for RAS proteins in mammalian cells.
Project description:MEK inhibition in combination with a glycogen synthase kinase-3β (GSK3β) inhibitor, referred as the 2i condition, favors pluripotency in embryonic stem cells (ESCs). However, the mechanisms by which the 2i condition limits ESC differentiation and whether RAS proteins are involved in this phenomenon remain poorly understood. Here we show that RAS nullyzygosity reduces the growth of mouse ESCs (mESCs) and prohibits their differentiation. Upon RAS deficiency or MEK inhibition, ERF (E twenty-six 2 [Ets2]-repressive factor), a transcriptional repressor from the ETS domain family, translocates to the nucleus, where it binds to the enhancers of pluripotency factors and key RAS targets. Remarkably, deletion of Erf rescues the proliferative defects of RAS-devoid mESCs and restores their capacity to differentiate. Furthermore, we show that Erf loss enables the development of RAS nullyzygous teratomas. In summary, this work reveals an essential role for RAS proteins in pluripotency and identifies ERF as a key mediator of the response to RAS/MEK/ERK inhibition in mESCs.
Project description:The naïve epiblast undergoes a transition to a pluripotent primed state during embryo implantation. Interestingly, a distinct intermediate stage during the naïve-to-primed transition has been recently described, the rosette stage. We propose the transcriptional repressor ERF as the MAPK-dependent switch that controls the exit from the rosette-stage of pluripotency. By using inducible ESC to genetically eliminate all RAS proteins, we show that, while differentiated RasKO ESC are reminiscent of the pluripotent rosette-stage, the absence of ERF overcomes the developmental blockage of RAS-deficient cells from this intermediate state. RNAseq data revealed that deletion of ERF restored the overall gene expression profile to a wild-type level in differentiated RasKO ESC. Mechanistically, ERF ensures naïve pluripotency by strengthening naïve pluripotent transcription factor binding and accessibility at specific ESC enhancers. Moreover, ERF regulates negatively the expression of the DNMT3 de novo methylases, which are essential for the extinction of the naïve transcriptional program. Our data revealed an essential role for ERF in the exit from rosette pluripotency as a regulator of the progression to primed pluripotency.
Project description:The naïve epiblast undergoes a transition to a pluripotent primed state during embryo implantation. Interestingly, a distinct intermediate stage during the naïve-to-primed transition has been recently described, the rosette stage. We propose the transcriptional repressor ERF as the MAPK-dependent switch that controls the exit from the rosette-stage of pluripotency. By using inducible ESC to genetically eliminate all RAS proteins, we show that, while differentiated RasKO ESC are reminiscent of the pluripotent rosette-stage, the absence of ERF overcomes the developmental blockage of RAS-deficient cells from this intermediate state. RNAseq data revealed that deletion of ERF restored the overall gene expression profile to a wild-type level in differentiated RasKO ESC. Mechanistically, ERF ensures naïve pluripotency by strengthening naïve pluripotent transcription factor binding and accessibility at specific ESC enhancers. Moreover, ERF regulates negatively the expression of the DNMT3 de novo methylases, which are essential for the extinction of the naïve transcriptional program. Our data revealed an essential role for ERF in the exit from rosette pluripotency as a regulator of the progression to primed pluripotency.
Project description:The naïve epiblast undergoes a transition to a pluripotent primed state during embryo implantation. Interestingly, a distinct intermediate stage during the naïve-to-primed transition has been recently described, the rosette stage. We propose the transcriptional repressor ERF as the MAPK-dependent switch that controls the exit from the rosette-stage of pluripotency. By using inducible ESC to genetically eliminate all RAS proteins, we show that, while differentiated RasKO ESC are reminiscent of the pluripotent rosette-stage, the absence of ERF overcomes the developmental blockage of RAS-deficient cells from this intermediate state. RNAseq data revealed that deletion of ERF restored the overall gene expression profile to a wild-type level in differentiated RasKO ESC. Mechanistically, ERF ensures naïve pluripotency by strengthening naïve pluripotent transcription factor binding and accessibility at specific ESC enhancers. Moreover, ERF regulates negatively the expression of the DNMT3 de novo methylases, which are essential for the extinction of the naïve transcriptional program. Our data revealed an essential role for ERF in the exit from rosette pluripotency as a regulator of the progression to primed pluripotency.