T cell receptor-associated alpha-phosphatidylinositol 3-kinase becomes activated by T cell receptor cross-linking and requires pp56lck.
The activation of a phosphatidylinositol (PI) 3-kinase is one of the earliest intracellular responses to T lymphocyte stimulation. We have used a human T cell line, Jurkat, and an antibody that recognizes the clonotype of its T cell receptor (TcR) to characterize the association of PI 3-kinase with the TcR and its activation in response to TcR cross-linking. We show that the TcR is constitutively associated with the alpha isoform of the PI 3-kinase p85 regulatory subunit. Stimulation of Jurkat cells through the TcR results in the rapid and transient activation of the associated PI 3-kinase. In addition, our results indicate that the tyrosine kinase pp56lck is essential for PI 3-kinase activation via the TcR.
Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Universidad Autonoma, Madrid, Spain.
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AC
Carrera
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L
Rodriguez-Borlado
C
C
Martinez-Alonso
I
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Merida
D003432:Cross-Linking Reagents; D004789:Enzyme Activation; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000502:physiology; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D046911:Macromolecular Substances; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism*
D003432:Cross-Linking Reagents; D007527:Isoenzymes; D046911:Macromolecular Substances; D011948:Receptors, Antigen, T-Cell; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D011505:Protein-Tyrosine Kinases; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck)