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Spatial and Temporal Analysis of Active ERK in the C. elegans Germline
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Spatial and Temporal Analysis of Active ERK in the C. elegans Germline

Published on: November 29, 2016

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A negative-feedback loop regulating ERK1/2 activation and mediated by RasGPR2 phosphorylation

Jinqi Ren1, Aaron A Cook2, Wolfgang Bergmeier2

  • 1Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599.

Biochemical and Biophysical Research Communications
|April 25, 2016
PubMed

Insights

Phosphorylation of RasGRP2 by ERK1/2 inhibits its activity, creating a negative-feedback loop that controls ERK1/2 signaling. This finding reveals a novel mechanism regulating cell proliferation and survival pathways.

Area of Science:

  • Cellular signaling pathways
  • Molecular biology
  • Biochemistry

Background:

  • Extracellular signal-regulated kinases (ERK1/2) are crucial for cell functions like proliferation and survival.
  • The precise mechanisms governing ERK1/2 activation remain incompletely understood.

Purpose of the Study:

  • To investigate the regulatory mechanisms of ERK1/2 activation.
  • To identify novel substrates and feedback loops within the ERK signaling cascade.

Main Methods:

  • Investigated the effect of RasGRP2 phosphorylation on ERK1/2 activation.
  • Utilized biochemical assays to identify the phosphorylation site on RasGRP2.
  • Analyzed the impact of this phosphorylation on the BRAF-MEK-ERK pathway.

Main Results:

  • Phosphorylation of RasGRP2 by ERK2 at Ser394 inhibits its guanine nucleotide exchange factor (GEF) activity.
  • This inhibition reduces the activation of the small GTPase Rap1.
  • Consequently, RasGRP2 phosphorylation leads to decreased ERK1/2 activation, establishing a negative-feedback loop.

Conclusions:

  • RasGRP2 is a novel substrate of ERK1/2.
  • A negative-feedback mechanism involving RasGRP2 regulates the BRAF-MEK-ERK signaling cascade.
  • This feedback loop fine-tunes the amplitude and duration of ERK1/2 activity, impacting cell fate decisions.
Keywords:
CalDAG-GEFIERK1/2 signalingGEFNegative-feedback loopPhosphorylationRasGRP2

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