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CNK, a RAF-binding multidomain protein required for RAS signaling

M Therrien1, A M Wong, G M Rubin

  • 1Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA.

Cell
|November 14, 1998
PubMed

Insights

Connector enhancer of ksr (CNK) is a novel protein that functions in the RAS/MAPK pathway. CNK interacts with RAF and regulates its function and localization, impacting signal transmission.

Area of Science:

  • Molecular biology
  • Cell signaling
  • Genetics

Background:

  • Kinase suppressor of ras (KSR) is crucial for RAS/MAPK cascade signal transmission.
  • The RAS/MAPK pathway regulates fundamental cellular processes, including proliferation and differentiation.

Purpose of the Study:

  • To identify novel genes involved in the RAS/MAPK pathway.
  • To elucidate the function and mechanism of the newly identified gene, connector enhancer of ksr (CNK).

Main Methods:

  • Genetic screens to identify modifier mutations.
  • Protein interaction studies.
  • Subcellular localization analysis.

Main Results:

  • A novel gene, connector enhancer of ksr (CNK), was identified.
  • CNK functions upstream or in parallel to RAF in the RAS pathway.
  • CNK protein possesses protein-protein interaction domains, is tyrosine phosphorylated, interacts with RAF, and localizes to cell-cell contact regions.

Conclusions:

  • CNK is a novel component of RAS-dependent signaling pathways.
  • CNK regulates RAF function and/or localization upon RAS activation.
  • CNK acts as a scaffold protein, bringing signaling molecules together.

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