phosphorus-radioisotopes and Leukemia--T-Cell

phosphorus-radioisotopes has been researched along with Leukemia--T-Cell* in 2 studies

Other Studies

2 other study(ies) available for phosphorus-radioisotopes and Leukemia--T-Cell

ArticleYear
Application of polyacrylamide gel electrophoresis for analysis of oligopeptide phosphorylation in vitro.
    BioTechniques, 1995, Volume: 18, Issue:4

    Topics: Adenosine Triphosphate; Amino Acid Sequence; Electrophoresis, Polyacrylamide Gel; Humans; Leukemia, T-Cell; Molecular Sequence Data; Oligopeptides; Phosphopeptides; Phosphorus Radioisotopes; Phosphorylation; Precipitin Tests; Protein-Tyrosine Kinases; Tumor Cells, Cultured

1995
Dephosphorylation and activation of the T cell tyrosine kinase pp56lck by the leukocyte common antigen (CD45).
    Oncogene, 1990, Volume: 5, Issue:6

    pp56lck, encoded by the lck proto-oncogene, is a non-receptor tyrosine protein kinase (TPK) found in all T lymphocytes. A significant fraction of pp56lck is tightly associated with the cytoplasmic domains of CD4 and CD8 glycoproteins, suggesting an important role for it in thymic development and T cell activation. We have studied the regulation of the tyrosine kinase activity of pp56lck and found recently that it becomes rapidly activated in isolated T cell membranes by an endogenous mechanism apparently involving a phosphotyrosine phosphatase (PTPase). Moreover pp56lck was activated upon addition of isolated CD45 (leukocyte common antigen), a major membrane PTPase, and activation was absent in T cell mutants lacking CD45. Here, we address in more detail the mechanisms of pp56lck activation by the CD45 PTPase and show that this event is time-dependent, sensitive to Na3VO4 (which blocks the PTPase activity of CD45), and is accompanied by dephosphorylation of a regulatory tyrosine residue (Tyr-505) near the C-terminus of pp56lck. This provides a molecular mechanism for regulation of the catalytic activity of pp56lck by CD45, which thus is likely to be the physiological activator of pp56lck. Activation of pp56lck by the CD45 PTPase may underlie many of the reported immunomodulatory effects of antibodies to CD45, and provides further support for the notion that CD45-mediated tyrosine dephosphorylation plays a critical role in T cell activation and growth.

    Topics: Antigens, Differentiation; Cell Line; Enzyme Activation; Histocompatibility Antigens; Humans; Immunohistochemistry; Leukemia, T-Cell; Leukocyte Common Antigens; Lymphocyte Specific Protein Tyrosine Kinase p56(lck); Phosphorus Radioisotopes; Phosphorylation; Protein-Tyrosine Kinases; Proto-Oncogene Mas; T-Lymphocytes

1990