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RhoC GTPase Activation Assay

Published on: August 23, 2010

Suppression of Ras-induced apoptosis by the Rac GTPase

T Joneson1, D Bar-Sagi

  • 1Department of Molecular Genetics and Microbiology, State University of New York at Stony Brook, Stony Brook, New York 11794-5222, USA.

Molecular and Cellular Biology
|August 24, 1999
PubMed

Insights

High Ras signaling triggers cell death (apoptosis), but Rac protein can block this effect. Rac

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Oncology

Background:

  • Ras proteins are key regulators of cell signaling pathways controlling proliferation, differentiation, and survival.
  • Dysregulation of Ras signaling is implicated in various cancers.
  • Understanding cellular responses to oncogenic Ras is crucial for cancer research.

Purpose of the Study:

  • To investigate cellular responses to high-intensity Ras signaling.
  • To elucidate the role of Rac in modulating Ras-induced apoptosis.
  • To identify downstream pathways involved in Ras-mediated cell death.

Main Methods:

  • Overexpression of oncogenic HRasV12 in primary and immortalized cells.
  • Manipulation of Rac activity (activation and dominant interference).
  • Analysis of apoptosis induction and signaling pathway activation (ERK, JNK, NF-kappaB).

Main Results:

  • HRasV12 expression induces apoptosis in a dose-dependent manner.
  • Activated Rac suppresses HRasV12-induced apoptosis, while dominant interfering Rac potentiates it.
  • Rac's suppressive effect is linked to insert region effectors and NF-kappaB activation.
  • HRasV12-induced apoptosis requires ERK and JNK activation and is p53-independent.

Conclusions:

  • Rac plays a critical role in regulating cell survival signals.
  • Rac can suppress Ras-induced apoptosis through specific effector pathways.
  • Rac activity may confer a growth advantage in Ras-transformed cells, relevant to oncogenesis.

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