TY - JOUR TI - Lineage commitment of embryonic cells involves MEK1-dependent clearance of pluripotency regulator Ventx2 AU - Scerbo, Pierluigi AU - Marchal, Leslie AU - Kodjabachian, Laurent A2 - Rubin, Lee L VL - 6 PY - 2017 DA - 2017/06/27 SP - e21526 C1 - eLife 2017;6:e21526 DO - 10.7554/eLife.21526 UR - https://doi.org/10.7554/eLife.21526 AB - During early embryogenesis, cells must exit pluripotency and commit to multiple lineages in all germ-layers. How this transition is operated in vivo is poorly understood. Here, we report that MEK1 and the Nanog-related transcription factor Ventx2 coordinate this transition. MEK1 was required to make Xenopus pluripotent cells competent to respond to all cell fate inducers tested. Importantly, MEK1 activity was necessary to clear the pluripotency protein Ventx2 at the onset of gastrulation. Thus, concomitant MEK1 and Ventx2 knockdown restored the competence of embryonic cells to differentiate. Strikingly, MEK1 appeared to control the asymmetric inheritance of Ventx2 protein following cell division. Consistently, when Ventx2 lacked a functional PEST-destruction motif, it was stabilized, displayed symmetric distribution during cell division and could efficiently maintain pluripotency gene expression over time. We suggest that asymmetric clearance of pluripotency regulators may represent an important mechanism to ensure the progressive assembly of primitive embryonic tissues. KW - pluripotency KW - xenopus KW - MEK1 KW - asymmetric division KW - Ventx JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -