Related Experiment Video

Updated: Nov 6, 2025

Identifying the Binding Proteins of Small Ligands with the Differential Radial Capillary Action of Ligand Assay DRaCALA
09:26

Identifying the Binding Proteins of Small Ligands with the Differential Radial Capillary Action of Ligand Assay DRaCALA

Published on: March 19, 2021

3.7K

A signalling cascade for Ral

You Wu, David J Reiner1

  • 1Texas A&M University, Houston, TX, USA.

Small Gtpases
|May 6, 2021
PubMed

Insights

Ras signaling through RalGEF>Ral is poorly understood. Invertebrate studies reveal a Ras>RalGEF>Ral>GCK-2>p38 MAP kinase cascade, clarifying Ras effector pathway functions in vivo.

Area of Science:

  • Cellular signaling pathways
  • Oncogenic signaling
  • MAP kinase cascades

Background:

  • Ras is a key oncoprotein in cancer, with RalGEF>Ral signaling being the least understood effector pathway.
  • Previous research in Drosophila identified Ral's role in apoptosis and its links to MAP4 Kinase misshapen and JNK MAP kinase basket.
  • Key signaling components differ between model organisms, necessitating studies in organisms like C. elegans.

Approach:

  • Utilized C. elegans vulval precursor cell (VPC) development for analyzing Ras signaling pathways.
  • Investigated the functions of paralogous CNH-domain MAP4 Kinases MIG-15 and GCK-2 in relation to Ras>Raf, Notch, and Ras>RalGEF>Ral signaling.
  • Employed CRISPR and genetic epistasis to delineate the Ras>RalGEF>Ral signaling cascade.

Key Points:

  • MIG-15 (nematode misshapen ortholog) antagonizes both Ral-dependent and Ras>Raf-dependent outcomes in VPC development.
  • GCK-2 (C. elegans happyhour ortholog) propagates Ral's pro-developmental signal.
  • A Ras>RalGEF>Ral>Exo84>GCK-2>MAP3K^MLK-1>p38^PMK-1 cascade was defined.

Conclusions:

  • Genetic analysis in invertebrate models elucidated a novel signaling cascade from Ras to p38 MAP kinase via the RalGEF>Ral pathway.
  • This research provides crucial insights into the in vivo function of Ral signaling, a critical but understudied Ras effector.
Keywords:
Exo84Exoc-8ExocystLET-60MLK-1PMK-1Ral-1Rgl-1Sec-5Sec5hppymsn

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