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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
27
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pubmed:dateCreated |
1993-10-20
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pubmed:abstractText |
The relative levels of phosphatidylinositol-3'-kinase (PI3K) activity were measured in interleukin-2 (IL-2)-dependent helper (HT-2) and cytolytic (CTLL-2) T-cell clones that had been stably transfected with expression plasmids encoding either the normal p56-Lck kinase or a mutant version of this kinase, p56-Lck(Y505F), that has constitutively high levels of kinase activity. Stimulation of untransfected T-cells or of transfected T-cells containing increased levels of normal p56-Lck resulted in an approximate doubling of the relative amounts of total cellular PI3K activity. In contrast, T-cells producing the activated version of p56-Lck contained levels of PI3K activity comparable to or slightly higher than those found IL-2-stimulated control cells, even in the absence of IL-2. Assessments of the relative levels of PI3K activity in immunoprecipitates prepared with the use of anti-phosphotyrosine-specific antibodies revealed constitutively high levels of anti-phosphotyrosine-immunoprecipitable PI3K activity in T-cells containing p56-Lck(Y505F), as opposed to T-cells containing normal p56-Lck where increases in anti-PY-immunoprecipitable PI3K activity were IL-2-inducible. IL-2 stimulation of T-cells containing the normal p56-Lck kinase resulted in marked increases in the relative amounts of PI3K activity and p85 that were coimmunoprecipitated when using anti-p56-Lck antibodies. In contrast, PI3K activity and the p85 subunit of PI3K could be coimmunoprecipitated from T-cells producing the activated p56-Lck(Y505F) kinase even in the absence of IL-2 stimulation, implying constitutive association of PI3K with the activated Lck kinase. Taken together with previous studies showing that IL-2 induces rapid increases in the activities of both p56-Lck and PI3K in T-cells, these findings suggest that p56-Lck lies immediately upstream of PI3K in a signal transduction cascade initiated by the binding of IL-2 to its specific receptor on T-lymphocytes.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Antibodies,
http://linkedlifedata.com/resource/pubmed/chemical/Interleukin-2,
http://linkedlifedata.com/resource/pubmed/chemical/Lymphocyte Specific Protein...,
http://linkedlifedata.com/resource/pubmed/chemical/Peptides,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphotransferases,
http://linkedlifedata.com/resource/pubmed/chemical/Protein-Tyrosine Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
268
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
20031-6
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pubmed:dateRevised |
2010-11-18
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pubmed:meshHeading |
pubmed-meshheading:8397196-Amino Acid Sequence,
pubmed-meshheading:8397196-Animals,
pubmed-meshheading:8397196-Antibodies,
pubmed-meshheading:8397196-Cells, Cultured,
pubmed-meshheading:8397196-Immunoblotting,
pubmed-meshheading:8397196-Interleukin-2,
pubmed-meshheading:8397196-Lymphocyte Specific Protein Tyrosine Kinase p56(lck),
pubmed-meshheading:8397196-Mice,
pubmed-meshheading:8397196-Molecular Sequence Data,
pubmed-meshheading:8397196-Peptides,
pubmed-meshheading:8397196-Phosphatidylinositol 3-Kinases,
pubmed-meshheading:8397196-Phosphotransferases,
pubmed-meshheading:8397196-Protein-Tyrosine Kinases,
pubmed-meshheading:8397196-Recombinant Proteins,
pubmed-meshheading:8397196-T-Lymphocytes, Cytotoxic,
pubmed-meshheading:8397196-T-Lymphocytes, Helper-Inducer,
pubmed-meshheading:8397196-Transfection
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pubmed:year |
1993
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pubmed:articleTitle |
Evidence that protein tyrosine kinase p56-Lck regulates the activity of phosphatidylinositol-3'-kinase in interleukin-2-dependent T-cells.
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pubmed:affiliation |
Department of Pathology & Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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