Negative feedback via RSK modulates Erk-dependent progression from naïve pluripotency

EMBO Rep. 2018 Aug;19(8):e45642. doi: 10.15252/embr.201745642. Epub 2018 Jun 12.

Abstract

Mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signalling is implicated in initiation of embryonic stem (ES) cell differentiation. The pathway is subject to complex feedback regulation. Here, we examined the ERK-responsive phosphoproteome in ES cells and identified the negative regulator RSK1 as a prominent target. We used CRISPR/Cas9 to create combinatorial mutations in RSK family genes. Genotypes that included homozygous null mutations in Rps6ka1, encoding RSK1, resulted in elevated ERK phosphorylation. These RSK-depleted ES cells exhibit altered kinetics of transition into differentiation, with accelerated downregulation of naïve pluripotency factors, precocious expression of transitional epiblast markers and early onset of lineage specification. We further show that chemical inhibition of RSK increases ERK phosphorylation and expedites ES cell transition without compromising multilineage potential. These findings demonstrate that the ERK activation profile influences the dynamics of pluripotency progression and highlight the role of signalling feedback in temporal control of cell state transitions.

Keywords: RSK; embryonic stem cells; mitogen‐activated protein kinase; pluripotency; signalling feedback.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation / drug effects
  • Cell Lineage / drug effects
  • Embryonic Stem Cells / cytology
  • Embryonic Stem Cells / drug effects
  • Embryonic Stem Cells / metabolism
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Feedback, Physiological* / drug effects
  • Humans
  • Mutation / genetics
  • Phosphoproteins / metabolism
  • Phosphorylation / drug effects
  • Pluripotent Stem Cells / cytology
  • Pluripotent Stem Cells / drug effects
  • Pluripotent Stem Cells / metabolism*
  • Proteome / metabolism
  • Ribosomal Protein S6 Kinases, 90-kDa / antagonists & inhibitors
  • Ribosomal Protein S6 Kinases, 90-kDa / genetics
  • Ribosomal Protein S6 Kinases, 90-kDa / metabolism*
  • Small Molecule Libraries / pharmacology

Substances

  • Phosphoproteins
  • Proteome
  • Small Molecule Libraries
  • Ribosomal Protein S6 Kinases, 90-kDa
  • Extracellular Signal-Regulated MAP Kinases