title: Identification of a novel interaction of 14-3-3 with p190RhoGEF.
abstract: Activation of Rho GTPases by guanine nucleotide exchange factors (GEFs) mediates a broad range of cytoskeletal alterations that determine cell shape. In the nervous system, Rho GTPases are essential for establishing highly asymmetrical neuronal forms and may fine-tune the shape of dendrites in differentiated neurons. p190RhoGEF is a brain-enriched, RhoA-specific GEF whose highly interactive C-terminal domain provides potential linkage to multiple pathways in the cell. In the present study, a yeast two-hybrid screen was used to identify 14-3-3eta and 14-3-3epsilon as additional binding partners of p190RhoGEF. Interactions between p190RhoGEF and 14-3-3eta were confirmed biochemically and by colocalization of the respective proteins when fused to fluorescent markers and transfected in neuronal cells. We also mapped a unique phosphorylation-independent binding site (I(1370)QAIQNL) in p190RhoGEF. Deletion of the binding site abolished interactions in vitro as well as the ability of 14-3-3eta to alter the cytoplasmic aggregation of p190RhoGEF in cotransfected cells. The findings suggest a potential role for 14-3-3 in modulating p190RhoGEF activity or in linking p190RhoGEF to the activities of other pathways in the neuron.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical School, Philadelphia, Pennsylvania 19104, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zhai
authors.forename: H
authors.initials: H
authors.lastname: Lin
authors.forename: M
authors.initials: M
authors.lastname: Shamim
authors.forename: W W
authors.initials: WW
authors.lastname: Schlaepfer
authors.forename: R
authors.initials: R
authors.lastname: Cañete-Soler
mesh_terms: D048948:14-3-3 Proteins; D000818:Animals; D001665:Binding Sites; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D012097:Repressor Proteins; D015398:Signal Transduction; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
chemical_list: D048948:14-3-3 Proteins; C513040:Arhgap35 protein, rat; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D009687:Nuclear Proteins; D012097:Repressor Proteins; D014446:Tyrosine 3-Monooxygenase