Membrane Glycoprotein IV (CD36) is Physically Associated with the Fyn, Lyn, and Yes Protein-Tyrosine Kinases in Human Platelets

• Published in: Proceedings of the National Academy of Sciences - PNAS 1991-09, Vol.88 (17), p.7844-7848
• Main Authors: MIN-MEI HUANG, BOLEN, J. B, BARNWELL, J. W, SHATTIL, S. J, BRUGGE, J. S
• Format: Article
• Language: English
• Subjects: Agonists; Analytical, structural and metabolic biochemistry; Antibodies; Antigens, CD - isolation & purification; Antigens, CD - metabolism; B lymphocytes; Biological and medical sciences; Blood Platelets - immunology; Blood Platelets - metabolism; CD36 Antigens; Cell lines; Cells; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Fyn protein; Genes, src; glycoprotein IV; Humans; Lyn protein; Myeloid cells; Phosphorylation; Platelet Membrane Glycoproteins - immunology; Platelet Membrane Glycoproteins - isolation & purification; Platelet Membrane Glycoproteins - metabolism; Platelets; Protein-Tyrosine Kinases - blood; Protein-Tyrosine Kinases - isolation & purification; Protein-Tyrosine Kinases - metabolism; Proto-Oncogene Proteins - blood; Proto-Oncogene Proteins - isolation & purification; Proto-Oncogene Proteins c-fyn; Proto-Oncogene Proteins c-yes; Receptors; src-Family Kinases; T lymphocytes; Transferases; Yes protein
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.88.17.7844

Activation of platelets with thrombin and other agonists causes a rapid increase in the phosphorylation of multiple proteins on tyrosine. To identify candidate proteintyrosine kinases (PTKs; EC 2.7.1.112) that may be responsible for these phosphorylation events, we analyzed the expression of seven Src-family PTKs and examined the association of these kinases with known platelet membrane glycoproteins. Five Src-related PTKs were detected in platelets: pp60SRC, pp60FYN, pp62YES, pp61HCK, and two LYN products of Mr54,000 and 58,000. The Fgr and Lck PTKs were not detected. Although strict comparative quantification of protein levels was not possible, pp60SRCwas detected at higher levels than any of the other kinases. In addition, glycoprotein IV (GPIV, CD36), one of the major platelet membrane glycoproteins, was associated in a complex with the Fyn, Yes, and Lyn proteins in platelet lysates. Similar complexes were also found in two GPIV-expressing cell lines, C32 melanoma cells and HEL cells. Since PTKs appear to be involved in stimulus-response coupling at the plasma membrane, these results suggest that ligand interaction with GPIV may activate signaling pathways that are triggered by tyrosine phosphorylation.