title: RalGEF2, a pleckstrin homology domain containing guanine nucleotide exchange factor for Ral.
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.
authors.affiliation: Department of Physiological Chemistry, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands.
authors.forename: K M
authors.initials: KM
authors.lastname: de Bruyn
authors.forename: J
authors.initials: J
authors.lastname: de Rooij
authors.forename: R M
authors.initials: RM
authors.lastname: Wolthuis
authors.forename: H
authors.initials: H
authors.lastname: Rehmann
authors.forename: J
authors.initials: J
authors.lastname: Wesenbeek
authors.forename: R H
authors.initials: RH
authors.lastname: Cool
authors.forename: A H
authors.initials: AH
authors.lastname: Wittinghofer
authors.forename: J L
authors.initials: JL
authors.lastname: Bos
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism; D019556:COS Cells; D004789:Enzyme Activation; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D020725:ral GTP-Binding Proteins / Q000378:metabolism*; D020726:ral Guanine Nucleotide Exchange Factor / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*
chemical_list: D001798:Blood Proteins; D010750:Phosphoproteins; C039077:platelet protein P47; D020726:ral Guanine Nucleotide Exchange Factor; D020725:ral GTP-Binding Proteins