1. RalGEF2, a pleckstrin homology domain containing guanine nucleotide exchange factor for Ral.
- Author
-
de Bruyn KM, de Rooij J, Wolthuis RM, Rehmann H, Wesenbeek J, Cool RH, Wittinghofer AH, and Bos JL
- Subjects
- Amino Acid Sequence, Animals, Blood Proteins genetics, Blood Proteins metabolism, COS Cells, Enzyme Activation, Molecular Sequence Data, Phosphoproteins genetics, Phosphoproteins metabolism, Sequence Alignment, Substrate Specificity, ral Guanine Nucleotide Exchange Factor genetics, ral GTP-Binding Proteins metabolism, ral Guanine Nucleotide Exchange Factor analysis, ral Guanine Nucleotide Exchange Factor metabolism
- Abstract
Ral is a ubiquitously expressed Ras-like small GTPase. Several guanine nucleotide exchange factors for Ral have been identified, including members of the RalGDS family, which exhibit a Ras binding domain and are regulated by binding to RasGTP. Here we describe a novel type of RalGEF, RalGEF2. This guanine nucleotide exchange factor has a characteristic Cdc25-like catalytic domain at the N terminus and a pleckstrin homology (PH) domain at the C terminus. RalGEF2 is able to activate Ral both in vivo and in vitro. Deletion of the PH domain results in an increased cytoplasmic localization of the protein and a corresponding reduction in activity in vivo, suggesting that the PH domain functions as a membrane anchor necessary for optimal activity in vivo.
- Published
- 2000
- Full Text
- View/download PDF