Modification of p115RhoGEF Ser(330) regulates its RhoGEF activity

Cell Signal. 2013 Nov;25(11):2085-92. doi: 10.1016/j.cellsig.2013.06.012. Epub 2013 Jun 29.


p115RhoGEF is a member of a family of Rho-specific guanine nucleotide exchange factors that also contains a regulator of G protein signaling homology domain (RH-RhoGEFs) that serves as a link between Gα13 signaling and RhoA activation. While the mechanism of regulation of p115RhoGEF by Gα13 is becoming well-known, the role of other regulatory mechanisms, such as post-translational modification or autoinhibition, in mediating p115RhoGEF activity is less well-characterized. Here, putative phosphorylation sites on p115RhoGEF are identified and characterized. Mutation of Ser(330) leads to a decrease in serum response element-mediated transcription as well as decreased activation by Gα13 in vitro. Additionally, this study provides the first report of the binding kinetics between full-length p115RhoGEF and RhoA in its various nucleotide states and examines the binding kinetics of phospho-mutant p115RhoGEF to RhoA. These data, together with other recent reports on regulatory mechanisms of p115RhoGEF, suggest that this putative phosphorylation site serves as a means for initiation or relief of autoinhibition of p115RhoGEF, providing further insight into the regulation of its activity.

Keywords: ATRA; All-trans retinoic acid; DH; DMEM; Dbl homology; Dulbecco's modified Eagle's medium; FBS; Fetal bovine serum; GAP; GTPase activating protein; Galpha13; HPLC–MS/MS; High pressure/tandem mass spectrometry; LARG; LC/MS/MS; LPA; Leukemia-associated RhoGEF; Liquid chromatography/tandem mass spectrometry; Lysophosphatidic acid; Nα-p-tosyl-l-lysine phenylalanine chloromethyl ketone; Nα-tosyl-l-lysine chloromethyl ketone; PAR-1; PDZ; PH; PMA; Phorbol 12-myristate 13-acetate; Pleckstrin homology; Post-synaptic density protein, discs large protein, zonula occludens-1; Protease-activated receptor 1; RH-RhoGEF; RU; Regulator of G protein signaling homology domain-containing Rho guanine nucleotide exchange factor; Response units; RhoA; S1P; SPR; Sf9; Signal transduction; Sphingosine-1-phosphate; Spodoptera frugiperda; Surface plasmon resonance; TLCK; TPCK; p115RhoGEF.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Line, Tumor
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • GTP-Binding Protein alpha Subunits, G12-G13 / genetics
  • GTP-Binding Protein alpha Subunits, G12-G13 / metabolism*
  • Gene Expression Regulation*
  • Genes, Reporter
  • Humans
  • Kinetics
  • Luciferases / genetics
  • Luciferases / metabolism
  • Molecular Sequence Data
  • Mutation
  • Phosphorylation
  • Protein Binding
  • Protein Processing, Post-Translational*
  • Protein Structure, Secondary
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Rho Guanine Nucleotide Exchange Factors / genetics
  • Rho Guanine Nucleotide Exchange Factors / metabolism*
  • Serine / metabolism*
  • Serum Response Element
  • Signal Transduction
  • rhoA GTP-Binding Protein / genetics
  • rhoA GTP-Binding Protein / metabolism*


  • Recombinant Proteins
  • Rho Guanine Nucleotide Exchange Factors
  • Serine
  • Luciferases
  • GTP-Binding Protein alpha Subunits, G12-G13
  • rhoA GTP-Binding Protein