Related Experiment Video

Updated: Jun 26, 2026

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods
07:49

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods

Published on: July 17, 2019

Positive- and negative-feedback regulations coordinate the dynamic behavior of the Ras-Raf-MEK-ERK signal

Sung-Young Shin1, Oliver Rath, Sang-Mok Choo

  • 1Department of Bio and Brain Engineering and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.

Journal of Cell Science
|January 23, 2009
PubMed

Insights

The study reveals how feedback loops and RKIP regulate the ERK pathway. These mechanisms create oscillations and switch-like behaviors, crucial for cell signaling dynamics.

Area of Science:

  • Cellular signaling
  • Molecular biology
  • Systems biology

Background:

  • The Ras-Raf-MEK-ERK pathway regulates cell proliferation, survival, and differentiation.
  • The precise roles of feedback mechanisms, especially Raf kinase inhibitor protein (RKIP), in ERK pathway dynamics remain unclear.

Purpose of the Study:

  • To investigate the complex feedback loops within the ERK pathway.
  • To elucidate the specific function of RKIP in regulating pathway dynamics.
  • To understand how these elements collectively shape cellular responses.

Main Methods:

  • Combined biochemical experiments with in silico simulations.
  • Developed and utilized an experimentally validated mathematical model.
  • Analyzed the impact of feedback loops and RKIP on pathway behavior.

Main Results:

  • Identified a crucial negative-feedback loop (ERK to SOS) driving ERK activity oscillations.
  • Demonstrated that a positive-feedback loop (ERK inactivating RKIP) enhances ERK oscillations.
  • Showed RKIP induces switch-like MEK activity and causes delayed, reduced ERK responses upon overexpression.

Conclusions:

  • Positive and negative feedback loops, along with RKIP, are essential regulators of ERK pathway dynamics.
  • These interactions generate complex oscillatory and switch-like behaviors in cellular signaling.
  • Understanding these dynamics is key to comprehending cell fate decisions.

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