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Updated: Aug 24, 2026

Detection of Small GTPase Prenylation and GTP Binding Using Membrane Fractionation and GTPase-linked Immunosorbent Assay
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Detection of Small GTPase Prenylation and GTP Binding Using Membrane Fractionation and GTPase-linked Immunosorbent Assay

Published on: November 11, 2018

Galectin-1(L11A) predicted from a computed galectin-1 farnesyl-binding pocket selectively inhibits Ras-GTP

Barak Rotblat1, Hagit Niv, Sabine André

  • 1Department of Neurobiochemistry, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.

Cancer Research
|May 6, 2004
PubMed

Insights

Galectin-1 binds Ras proteins, crucial for cell signaling. A modified galectin-1 (L11A) blocks Ras activity and membrane attachment, inhibiting cancer cell growth.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Ras proteins require membrane anchorage for biological activity.
  • Ras/galectin-1 interactions enhance Ras membrane anchorage.
  • Galectin-1 possesses a hydrophobic pocket similar to RhoGDI's Cdc42-binding cavity.

Purpose of the Study:

  • To investigate the role of galectin-1's hydrophobic pocket in Ras binding and activity.
  • To determine if galectin-1 can be engineered to inhibit Ras signaling.

Main Methods:

  • Site-directed mutagenesis of galectin-1 (L11A substitution).
  • Assays for Ras GTP-loading, ERK activation, and cell membrane association.
  • Evaluation of H-Ras(G12V)-induced fibroblast transformation and PC12-cell neurite outgrowth.

Main Results:

  • Galectin-1(L11A) retained carbohydrate-binding but inhibited H-Ras GTP-loading and ERK activation.
  • Galectin-1(L11A) dislodged H-Ras(G12V) from the cell membrane.
  • Galectin-1(L11A) attenuated H-Ras(G12V)-driven fibroblast transformation and PC12-cell neurite outgrowth.

Conclusions:

  • Galectin-1 directly cooperates with Ras independently of its carbohydrate-binding function.
  • The L11A mutation in galectin-1 creates a dominant-negative inhibitor of Ras signaling.
  • Targeting the galectin-1 hydrophobic pocket offers a novel strategy for inhibiting Ras-driven processes.

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