title: Pleiotropic defects in TCR signaling in a Vav-1-null Jurkat T-cell line.
abstract: The Rac/Rho-specific guanine nucleotide exchange factor, Vav-1, is a key component of the T-cell antigen receptor (TCR)-linked signaling machinery. Here we have used somatic cell gene-targeting technology to generate a Vav-1-deficient Jurkat T-cell line. The J.Vav1 cell line exhibits dramatic defects in TCR-dependent interleukin (IL)-2 promoter activation, accompanied by significant reductions in the activities of the NFAT(IL-2), NFkappaB, AP-1 and REAP transcription factors that bind to the IL-2 promoter region. In contrast, loss of Vav-1 had variable effects on early TCR-stimulated signaling events. J.Vav1 cells display a selective defect in sustained Ca(2+) signaling during TCR stimulation, and complementation of this abnormality by exogenously introduced Vav-1 is dependent on the Vav-1 calponin homology domain. While JNK activation was severely impaired, the stimulation of Ras, ERK and protein kinase C-theta activities, as well as the mobilization of lipid rafts, appeared normal in the J.Vav1 cells. Finally, evidence is presented to suggest that the alternative Vav family members, Vav-2 and Vav-3, are activated during TCR ligation, and partially compensate for the loss of Vav-1 in Jurkat T cells.
authors.affiliation: Department of Pharmacology and Cancer Biology and Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Youjia
authors.initials: Y
authors.lastname: Cao
authors.forename: Erin M
authors.initials: EM
authors.lastname: Janssen
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Duncan
authors.forename: Amnon
authors.initials: A
authors.lastname: Altman
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Billadeau
authors.forename: Robert T
authors.initials: RT
authors.lastname: Abraham
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D018797:Cell Cycle Proteins; D002458:Cell Fractionation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D018390:Gene Targeting; D020662:Guanine Nucleotide Exchange Factors; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D019169:Jurkat Cells; D021962:Membrane Microdomains / Q000378:metabolism; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000378:metabolism; D000074121:Protein Kinase C-theta; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D007376:Interleukin-2; D007527:Isoenzymes; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell; D018808:Transcription Factor AP-1; D014157:Transcription Factors; C496618:VAV1 protein, human; C496621:VAV3 protein, human; C496619:Vav1 protein, mouse; C496622:Vav3 protein, mouse; C076233:PRKCQ protein, human; C489593:Prkcq protein, mouse; D011493:Protein Kinase C; D000074121:Protein Kinase C-theta; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D002118:Calcium