Thy-1 glycoprotein and src-like protein-tyrosine kinase p53/p56lyn are associated in large detergent-resistant complexes in rat basophilic leukemia cells.
Thy-1 is a surface glycoprotein that is attached to the plasma membrane by a glycosyl-phosphatidyl-inositol anchor. Crosslinking of Thy-1 in rat mast cells and basophilic leukemia cells (RBL-2H3) induces cell activation including histamine release and tyrosine phosphorylation of several proteins. Here we show that glycosyl-phosphatidylinositol-linked Thy-1 forms noncovalent complexes with src-related protein-tyrosine kinase p53/p56lyn and other protein-tyrosine kinases and/or their substrates. These complexes are resistant to solubilization by a nonionic detergent, sedimentable at 200,000 x g, and very large ( > 10 MDa) as determined by gel chromatography. Activation of RBL-2H3 cells by crosslinking of the high-affinity IgE receptors resulted in decreased recovery of the complexes. The combined data indicate the existence of large detergent-resistant domains in the surface membrane of mast cells that may play an important role in their activation.
Dráberová
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Department of Mammalian Gene Expression, Czechoslovak Academy of Sciences, Prague.
Dráber
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D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000302:isolation & purification / Q000378:metabolism*; D000081247:CSK Tyrosine-Protein Kinase; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D015471:Leukemia, Basophilic, Acute; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D010727:Phosphoric Diester Hydrolases; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats; D017455:Receptors, IgE / Q000378:metabolism; D018800:Thy-1 Antigens; D014407:Tumor Cells, Cultured; D019061:src-Family Kinases
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D017455:Receptors, IgE; D018800:Thy-1 Antigens; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D016392:Proto-Oncogene Proteins pp60(c-src); C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; D010727:Phosphoric Diester Hydrolases; D043265:Phosphatidylinositol Diacylglycerol-Lyase