RalGDS-like factor (Rlf) is a novel Ras and Rap 1A-associating protein

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Updated: Nov 5, 2026

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
10:27

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells

Published on: March 9, 2012

R M Wolthuis1, B Bauer, L J van 't Veer

  • 1Laboratory for Physiological Chemistry, Utrecht University, The Netherlands.

Oncogene
|July 18, 1996
PubMed

Insights

Researchers identified a novel Rap 1A-interacting protein, Rlf, which acts as a Ral guanine nucleotide dissociation stimulator-like factor. Rlf directly binds to the GTP-bound forms of Ras and Rap 1A, suggesting it functions as an effector for these small GTPases.

Area of Science:

  • Molecular Biology
  • Cell Signaling
  • Oncogenesis

Background:

  • The small GTPase Rap 1A, related to Ras, can reverse Ras-induced oncogenic transformation.
  • Understanding Rap 1A and Ras signaling pathways is crucial for cancer research.

Purpose of the Study:

  • To identify novel proteins that interact with Rap 1A.
  • To characterize the function and binding properties of a newly discovered Rap 1A-interacting protein.

Main Methods:

  • Yeast two-hybrid screening of a mouse embryonic cDNA library.
  • In vitro binding assays to determine protein-protein interactions and binding affinities.

Main Results:

  • A novel Rap 1A-interacting protein, designated Rlf (RalGDS-like factor), was identified.
  • Rlf shares homology with Ral guanine nucleotide dissociation stimulator (RalGDS) and contains a Cdc25-homology domain.
  • Rlf specifically binds to the GTP-bound forms of Ras and Rap 1A with high affinity, but not their GDP-bound forms.

Conclusions:

  • Rlf is a putative effector for Ras and Rap 1A.
  • The discovery of Rlf provides new insights into the regulatory mechanisms of Ras and Rap 1A signaling pathways.

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