Identification of a novel guanine nucleotide exchange factor for the Rho GTPase

Matthew J. Hart, Sanju Sharma, Nadia Elmasry, Rong Guo Qiu, Peter McCabe, Paul Polakis, Gideon Bollag

Research output: Contribution to journalArticlepeer-review

139 Scopus citations


The Rho GTPase promotes proliferation and cytoskeletal rearrangements in mammalian cells. To understand the regulation of Rho, it is important to characterize guanine nucleotide exchange factors (GEFs), which stimulate the dissociation of GDP and subsequent binding of GTP. Using Rho as an affinity ligand, we have isolated a 115-kDa protein (p115-RhoGEF) that binds specifically to the nucleotide-depleted state. A full-length cDNA encoding p115-RhoGEF was isolated, and its protein product, which exhibited sequence homology to Dbl and Lbc, catalyzed the exchange of GDP for GTP specifically on Rho and not on the Rac, Cdc42, or Ras GTPases. p115-RhoGEF is capable of regulating cell proliferation, as determined by its ability to induce the transformation of NIH 3T3 cells. Northern and Western analysis suggests that p115-RhoGEF is ubiquitously expressed. These results indicate that p115- RhoGEF may be a general regulator of Rho and its associated cellular phenotypes.

Original languageEnglish (US)
Pages (from-to)25452-25458
Number of pages7
JournalJournal of Biological Chemistry
Issue number41
StatePublished - 1996
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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