DOCK7 is a critical regulator of the RAGE-Cdc42 signaling axis that induces formation of dendritic pseudopodia in human cancer cells

Oncol Rep. 2013 Mar;29(3):1073-9. doi: 10.3892/or.2012.2191. Epub 2012 Dec 17.

Abstract

Cellular migration is a fundamental process linked to cancer metastasis. Growing evidence indicates that the receptor for advanced glycation end products (RAGE) plays a pivotal role in this process. With regard to downstream signal transducers of RAGE, diaphanous-1 and activated small guanine nucleotide triphosphatases, Rac1 and Cdc42, have been identified. To obtain precise insight into the direct downstream signaling mechanism of RAGE, we screened for proteins interacting with the cytoplasmic domain of RAGE employing an immunoprecipitation-liquid chromatography coupled with an electrospray tandem mass spectrometry system. In the present study, we found that the cytoplasmic domain of RAGE interacted with an atypical DOCK180-related guanine nucleotide exchange factor, dedicator of cytokinesis protein 7 (DOCK7). DOCK7 bound to the RAGE cytoplasmic domain and transduced a signal to Cdc42, resulting in the formation of abundant highly branched filopodia-like protrusions, dendritic pseudopodia. Blocking of the function of DOCK7 greatly abrogated the formation of dendritic pseudopodia and suppressed cellular migration. These results indicate that DOCK7 functions as an essential and downstream regulator of RAGE-mediated cellular migration through the formation of dendritic pseudopodia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Movement
  • Dendrites / metabolism*
  • Enzyme Activation
  • GTPase-Activating Proteins / physiology*
  • Glioblastoma
  • Guanine Nucleotide Exchange Factors
  • HEK293 Cells
  • Humans
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Pseudopodia / metabolism*
  • Receptor for Advanced Glycation End Products / chemistry
  • Receptor for Advanced Glycation End Products / metabolism*
  • S100 Calcium Binding Protein beta Subunit / metabolism
  • Signal Transduction
  • cdc42 GTP-Binding Protein / metabolism*

Substances

  • DOCK7 protein, human
  • GTPase-Activating Proteins
  • Guanine Nucleotide Exchange Factors
  • Receptor for Advanced Glycation End Products
  • S100 Calcium Binding Protein beta Subunit
  • S100B protein, human
  • cdc42 GTP-Binding Protein