title: Residues Y429 and Y463 of the human CD5 are targeted by protein tyrosine kinases.
abstract: The human CD5 lymphocyte cell surface co-receptor modulates activation and differentiation responses mediated by the antigen-specific receptor of T and B cells. CD5 is phosphorylated following lymphocyte activation; however, the exact sites and kinases involved are yet to be determined. Jurkat T cell transfectants expressing tyrosine-mutated CD5 molecules have been used to show that residues Y429 and Y463 are targeted in vivo by protein tyrosine kinases following cell stimulation with anti-CD3 mAb or pervanadate. This is in agreement with data from direct in vitro kinase assays using purified recombinant Lck and Fyn protein tyrosine kinases. The analysis of Lck- and CD3-deficient Jurkat cells shows that tyrosine phosphorylation of CD5 requires Lck activity. We propose that T cell activation mediates CD5 tyrosine phosphorylation at residues Y429 and Y463 mainly through the activation of Lck.
authors: Servei d'Immunologia, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Barcelona, Spain.
authors: J M
authors: JM
authors: Vilà
authors: I
authors: I
authors: Gimferrer
authors: O
authors: O
authors: Padilla
authors: M
authors: M
authors: Arman
authors: L
authors: L
authors: Places
authors: M
authors: M
authors: Simarro
authors: J
authors: J
authors: Vives
authors: F
authors: F
authors: Lozano
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D017252:CD3 Complex / Q000235:genetics / Q000276:immunology; D018956:CD5 Antigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000187:drug effects; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation / Q000187:drug effects; D019000:Phosphotyrosine / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors; D011505:Protein-Tyrosine Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051076:Proto-Oncogene Proteins c-fyn; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D014162:Transfection; D014443:Tyrosine / Q000235:genetics / Q000378:metabolism*; D014638:Vanadates / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D018956:CD5 Antigens; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; C076715:pervanadate; D019000:Phosphotyrosine; D014638:Vanadates; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; C494957:FYN protein, human; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051076:Proto-Oncogene Proteins c-fyn; D017027:Protein Tyrosine Phosphatases