Developmental regulation of Erk signaling by mitotic kinases

ABSTRACT: At the blastocyst stage, the embryo invades the uterine and the pluripotent epiblast cells get reshaped from an amorphous ball into a polarized cup-shaped epithelium. At the same time, the transiently established naïve pluripotency is dismantled, transforming into a more developmentally advanced post-implantation pluripotent state. The major driver of the differentiation process is the autocrine Fgf/Mek/Erk singling which promotes the exit of naïve pluripotency. However, inhibiting Mek alone is not sufficient to maintain the cells in the naïve state suggesting the contribution of additional, as yet unidentified, pro-differentiation signals. Using a 3D embryonic stem cells (ESC) based model of epiblast development we established an automated pipeline for cell culture and analysis and performed a large-scale functional screen to identify factors regulating the development of the pluripotent lineage. We found that the mitotic kinases – Aurora kinase A (Aurka) and Polo-like kinase (PLK) positively regulate Erk signalling in a Mek-independent manner. We determined that Aurka and Erk form a complex in ESCs and suppression of Aurka activity delays the exit of naïve pluripotency. Moreover, a combination of Aurka and Mek inhibition enabled the de novo derivation of ESC lines from mouse embryos. Interestingly, during cell division, we found that phospho-Erk (pErk) localizes on the spindle poles at prophase and metaphase, gradually decreasing its signal at anaphase and telophase. Proximity biotinylation analysis of the pErk interactome identified the formation of PLK/pErk complex in metaphase cells. Moreover, inhibition of PLK, but not Mek or Aurka, resulted in a substantial decrease in Erk phosphorylation at the mitotic spindle. In summary, our findings demonstrate that the pluripotent cells continuously generate and perceive two types of Erk-mediated pro-differentiation cues - autocrine signals of the Fgf/Mek cascade and cell-intrinsic cues via the mitotic kinase Aurka and PLK. Altogether, these signals promote the exit of naïve pluripotency, driving the transient pace of embryonic development.

INSTRUMENT(S):

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Epiblast, Embryonic Stem Cell

SUBMITTER: Hannes Drexler  

LAB HEAD: Hannes Drexler

PROVIDER: PXD051298 | Pride | 2025-11-20

REPOSITORIES: Pride