MLK3 limits activated Galphaq signaling to Rho by binding to p63RhoGEF

Mol Cell. 2008 Oct 10;32(1):43-56. doi: 10.1016/j.molcel.2008.09.007.

Abstract

Mixed lineage kinase 3 (MLK3) is a MAP3K that activates the JNK-dependent MAPK pathways. Here, we show that MLK3 is required for cell migration in a manner independent of its role as a MAP3K or MLK3 kinase activity. Rather, MLK3 functions in a regulated way to limit levels of the activated GTPase Rho by binding to the Rho activator, p63RhoGEF/GEFT, which, in turn, prevents its activation by Galphaq. These findings demonstrate a scaffolding role for MLK3 in controlling the extent of Rho activation that modulates cell migration. Moreover, they suggest that MLK3 functions as a network hub that links a number of signaling pathways.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Line
  • Cell Movement / physiology
  • Cytoskeleton / ultrastructure
  • Focal Adhesions / ultrastructure
  • GTP-Binding Protein alpha Subunits, Gq-G11 / metabolism*
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Humans
  • In Vitro Techniques
  • MAP Kinase Kinase Kinases / antagonists & inhibitors
  • MAP Kinase Kinase Kinases / genetics
  • MAP Kinase Kinase Kinases / metabolism*
  • MAP Kinase Signaling System
  • Mitogen-Activated Protein Kinase Kinase Kinase 11
  • Models, Biological
  • Protein Binding
  • Pseudopodia / ultrastructure
  • RNA, Small Interfering / genetics
  • Receptors, G-Protein-Coupled / metabolism
  • Recombinant Fusion Proteins / metabolism
  • Rho Guanine Nucleotide Exchange Factors
  • Serum Response Factor / metabolism
  • Signal Transduction
  • rhoA GTP-Binding Protein / metabolism*

Substances

  • ARHGEF25 protein, human
  • Guanine Nucleotide Exchange Factors
  • RNA, Small Interfering
  • Receptors, G-Protein-Coupled
  • Recombinant Fusion Proteins
  • Rho Guanine Nucleotide Exchange Factors
  • SRF protein, human
  • Serum Response Factor
  • RHOA protein, human
  • MAP Kinase Kinase Kinases
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • rhoA GTP-Binding Protein