P-REX2, a novel PI-3-kinase sensitive Rac exchange factor

FEBS Lett. 2004 Aug 13;572(1-3):167-71. doi: 10.1016/j.febslet.2004.06.097.


We have identified an activator of Rac, P-REX2, that is structurally related to the exchange factor PtdIns(3,4,5)-dependent Rac exchanger (P-REX1), but exhibits distinct tissue-specific expression. P-REX2 is spliced into two RNA species, approximately 3.5 and approximately 10 kb in size. The cDNA corresponding to the smaller transcript encodes a protein that exhibits strong similarity with P-REX1 within its N-terminal domains, but differs in the C-terminal region. P-REX2 promoted increased levels of GTP-bound Rac that could be further stimulated by enhancing PI-3K activity. Thus, P-REX2 may serve as a novel link between Rac activation and the PI-3 kinase pathway.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Cell Line
  • Cloning, Molecular
  • Computational Biology
  • Fetus
  • GTPase-Activating Proteins / genetics
  • GTPase-Activating Proteins / metabolism*
  • Genes, Reporter
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Humans
  • Kidney
  • Luciferases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Protein Biosynthesis
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Transfection
  • rac GTP-Binding Proteins / metabolism*


  • GTPase-Activating Proteins
  • Guanine Nucleotide Exchange Factors
  • PREX1 protein, human
  • PREX2 protein, human
  • Recombinant Proteins
  • Luciferases
  • Phosphatidylinositol 3-Kinases
  • rac GTP-Binding Proteins