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dc.contributor.authorMeisner, Herman
dc.contributor.authorConway, Bruce R.
dc.contributor.authorHartley, David Alan
dc.contributor.authorCzech, Michael P.
dc.date2022-08-11T08:09:33.000
dc.date.accessioned2022-08-23T16:35:35Z
dc.date.available2022-08-23T16:35:35Z
dc.date.issued1995-07-01
dc.date.submitted2009-03-24
dc.identifier.citationMol Cell Biol. 1995 Jul;15(7):3571-8.
dc.identifier.issn0270-7306 (Print)
dc.identifier.pmid7791764
dc.identifier.urihttp://hdl.handle.net/20.500.14038/38592
dc.description.abstractT-cell receptor (TCR) cross-linking increases tyrosine phosphorylation of multiple proteins, only a few of which have been identified. One of the most rapidly tyrosine-phosphorylated polypeptides is the 120-kDa product of the proto-oncogene c-cbl, a cytosolic and cytoskeletal protein containing multiple proline-rich motifs that are potential binding sites for proteins containing Src homology 3 (SH3) domains. We report here that in cultured Jurkat T cells, Cbl is coprecipitated with antibody against the adapter protein Grb2. Upon activation of Jurkat T cells via the TCR-CD3 complex, we find that high-affinity binding of Cbl requires the N-terminal SH3 domain of GST-Grb2 fusion protein but after cross-linking of the TCR-CD3 and CD4 receptors, Cbl binds equally to its SH2 domain. Grb2 antisera also precipitated p85 from serum-starved cells, while TCR activation increased p85 and tyrosine-phosphorylated Cbl but not Cbl protein in Grb2 immunocomplexes. Phosphatidylinositol (PI) 3-kinase activity was immunoprecipitated from serum-starved cells with Cbl and to a lesser extent with Grb2 antisera, and TCR cross-linking increased this activity severalfold. The PI 3-kinase activity associated with Cbl amounted to 5 to 10% of the total cellular activity that could be precipitated by p85 antisera. The Ras exchange factor Son-of-sevenless 1 (Sos-1) was not found in anti-Cbl immunoprecipitates from activated cells, and Cbl was not detectable in anti-Sos-1 precipitates, supporting the likelihood that Sos-Grb2 and Cbl-Grb2 are present as distinct complexes. Taken together, these data suggest that Cbl function in Jurkat T cells involves its constitutive association with Grb2 and its recruitment of PI 3-kinase in response to TCR activation.
dc.language.isoen_US
dc.relation<a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&list_uids=7791764&dopt=Abstract">Link to Article in PubMed</a>
dc.subject1-Phosphatidylinositol 3-Kinase
dc.subject*Adaptor Proteins, Signal Transducing
dc.subjectAntigens, CD3
dc.subjectBase Sequence
dc.subjectBlotting, Western
dc.subjectGRB2 Adaptor Protein
dc.subjectLymphocyte Activation
dc.subjectMembrane Proteins
dc.subjectMolecular Sequence Data
dc.subjectPhosphotransferases (Alcohol Group Acceptor)
dc.subjectPrecipitin Tests
dc.subjectProtein Binding
dc.subjectProteins
dc.subjectProto-Oncogene Proteins
dc.subjectProto-Oncogene Proteins c-cbl
dc.subjectReceptors, Antigen, T-Cell
dc.subjectRecombinant Fusion Proteins
dc.subject*Signal Transduction
dc.subjectSon of Sevenless Proteins
dc.subjectT-Lymphocytes
dc.subject*Ubiquitin-Protein Ligases
dc.subjectLife Sciences
dc.subjectMedicine and Health Sciences
dc.titleInteractions of Cbl with Grb2 and phosphatidylinositol 3'-kinase in activated Jurkat cells
dc.typeJournal Article
dc.source.journaltitleMolecular and cellular biology
dc.source.volume15
dc.source.issue7
dc.identifier.legacyfulltexthttps://escholarship.umassmed.edu/cgi/viewcontent.cgi?article=2456&amp;context=oapubs&amp;unstamped=1
dc.identifier.legacycoverpagehttps://escholarship.umassmed.edu/oapubs/1457
dc.identifier.contextkey794954
refterms.dateFOA2022-08-23T16:35:35Z
html.description.abstract<p>T-cell receptor (TCR) cross-linking increases tyrosine phosphorylation of multiple proteins, only a few of which have been identified. One of the most rapidly tyrosine-phosphorylated polypeptides is the 120-kDa product of the proto-oncogene c-cbl, a cytosolic and cytoskeletal protein containing multiple proline-rich motifs that are potential binding sites for proteins containing Src homology 3 (SH3) domains. We report here that in cultured Jurkat T cells, Cbl is coprecipitated with antibody against the adapter protein Grb2. Upon activation of Jurkat T cells via the TCR-CD3 complex, we find that high-affinity binding of Cbl requires the N-terminal SH3 domain of GST-Grb2 fusion protein but after cross-linking of the TCR-CD3 and CD4 receptors, Cbl binds equally to its SH2 domain. Grb2 antisera also precipitated p85 from serum-starved cells, while TCR activation increased p85 and tyrosine-phosphorylated Cbl but not Cbl protein in Grb2 immunocomplexes. Phosphatidylinositol (PI) 3-kinase activity was immunoprecipitated from serum-starved cells with Cbl and to a lesser extent with Grb2 antisera, and TCR cross-linking increased this activity severalfold. The PI 3-kinase activity associated with Cbl amounted to 5 to 10% of the total cellular activity that could be precipitated by p85 antisera. The Ras exchange factor Son-of-sevenless 1 (Sos-1) was not found in anti-Cbl immunoprecipitates from activated cells, and Cbl was not detectable in anti-Sos-1 precipitates, supporting the likelihood that Sos-Grb2 and Cbl-Grb2 are present as distinct complexes. Taken together, these data suggest that Cbl function in Jurkat T cells involves its constitutive association with Grb2 and its recruitment of PI 3-kinase in response to TCR activation.</p>
dc.identifier.submissionpathoapubs/1457
dc.contributor.departmentProgram in Molecular Medicine
dc.contributor.departmentDepartment of Biochemistry and Molecular Biology
dc.source.pages3571-8


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