Interactions of Cbl with Grb2 and phosphatidylinositol 3'-kinase in activated Jurkat cells
dc.contributor.author | Meisner, Herman | |
dc.contributor.author | Conway, Bruce R. | |
dc.contributor.author | Hartley, David Alan | |
dc.contributor.author | Czech, Michael P. | |
dc.date | 2022-08-11T08:09:33.000 | |
dc.date.accessioned | 2022-08-23T16:35:35Z | |
dc.date.available | 2022-08-23T16:35:35Z | |
dc.date.issued | 1995-07-01 | |
dc.date.submitted | 2009-03-24 | |
dc.identifier.citation | Mol Cell Biol. 1995 Jul;15(7):3571-8. | |
dc.identifier.issn | 0270-7306 (Print) | |
dc.identifier.pmid | 7791764 | |
dc.identifier.uri | http://hdl.handle.net/20.500.14038/38592 | |
dc.description.abstract | 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. | |
dc.language.iso | en_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.subject | 1-Phosphatidylinositol 3-Kinase | |
dc.subject | *Adaptor Proteins, Signal Transducing | |
dc.subject | Antigens, CD3 | |
dc.subject | Base Sequence | |
dc.subject | Blotting, Western | |
dc.subject | GRB2 Adaptor Protein | |
dc.subject | Lymphocyte Activation | |
dc.subject | Membrane Proteins | |
dc.subject | Molecular Sequence Data | |
dc.subject | Phosphotransferases (Alcohol Group Acceptor) | |
dc.subject | Precipitin Tests | |
dc.subject | Protein Binding | |
dc.subject | Proteins | |
dc.subject | Proto-Oncogene Proteins | |
dc.subject | Proto-Oncogene Proteins c-cbl | |
dc.subject | Receptors, Antigen, T-Cell | |
dc.subject | Recombinant Fusion Proteins | |
dc.subject | *Signal Transduction | |
dc.subject | Son of Sevenless Proteins | |
dc.subject | T-Lymphocytes | |
dc.subject | *Ubiquitin-Protein Ligases | |
dc.subject | Life Sciences | |
dc.subject | Medicine and Health Sciences | |
dc.title | Interactions of Cbl with Grb2 and phosphatidylinositol 3'-kinase in activated Jurkat cells | |
dc.type | Journal Article | |
dc.source.journaltitle | Molecular and cellular biology | |
dc.source.volume | 15 | |
dc.source.issue | 7 | |
dc.identifier.legacyfulltext | https://escholarship.umassmed.edu/cgi/viewcontent.cgi?article=2456&context=oapubs&unstamped=1 | |
dc.identifier.legacycoverpage | https://escholarship.umassmed.edu/oapubs/1457 | |
dc.identifier.contextkey | 794954 | |
refterms.dateFOA | 2022-08-23T16:35:35Z | |
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.submissionpath | oapubs/1457 | |
dc.contributor.department | Program in Molecular Medicine | |
dc.contributor.department | Department of Biochemistry and Molecular Biology | |
dc.source.pages | 3571-8 |