The many faces of the guanine-nucleotide exchange factor trio

Cell Adh Migr. Nov-Dec 2012;6(6):482-7. doi: 10.4161/cam.21418. Epub 2012 Oct 17.


Small Rho-GTPases are enzymes that are bound to GDP or GTP, which determines their inactive or active state, respectively. The exchange of GDP for GTP is catalyzed by so-called Rho-guanine nucleotide exchange factors (GEFs). Rho-GEFs are characterized by a Dbl-homology (DH) and adjacent Pleckstrin-homology (PH) domain that serves as enzymatic unit for the GDP/GTP exchange. Rho-GEFs show different GTPase specificities, meaning that a particular GEF can activate either multiple GTPases or only one specific GTPase. We recently reported that the Rho-GEF Trio, known to be able to exchange GTP on Rac1, RhoG and RhoA, regulates lamellipodia formation to mediate cell spreading and migration in a Rac1-dependent manner. In this commentary, we review the current knowledge of Trio in several aspects of cell biology.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Movement
  • Enzyme Activation
  • Gene Expression Regulation, Neoplastic
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Humans
  • Leukocytes / metabolism
  • Leukocytes / pathology
  • Neurogenesis
  • Phosphorylation
  • Protein Interaction Mapping
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Pseudopodia / metabolism
  • rac1 GTP-Binding Protein / metabolism
  • src Homology Domains


  • Guanine Nucleotide Exchange Factors
  • RAC1 protein, human
  • KALRN protein, human
  • Protein-Serine-Threonine Kinases
  • TRIO protein, human
  • rac1 GTP-Binding Protein