Developmental regulation of ERK signaling by mitotic kinases

The morphogenesis of the mouse epiblast during implantation can be recapitulated by culturing its counterpart ES cells in growth factor reduced Matrigel. We analysed the transcripts level changes using Next-generation sequencing (NGS) technique with ES cells grown in Matrigel in N2B27 medium supplemented with 2iLif, FGF2/Activin, PD03259021, Aurka inh and PD032+ Aurka inh for 2 days. We found cells delayed exit of naïve pluripotency by inhibiting Aurka activity and this effect can be strengthened by combing Mek and Aurka inhibitors. By further pathways enrichment analysis, we found down regulation of MAPK signalling pathway after Aurka inhibition which is validated by Q-PCR and immunofluorescence. Our findings demonstrate 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.