Alterations in tyrosine protein phosphorylation induced by antibody-mediated cross-linking of the CD4 receptor of T lymphocytes.
AUTOR(ES)
Veillette, A
RESUMO
Accumulating data suggest that the CD4 T-cell surface antigen transduces an independent intracellular signal during antigen-mediated T-cell activation. CD4 is physically associated with the internal membrane tyrosine protein kinase p56lck and can mediate, after antibody-mediated cross-linking, the rapid enzymatic activation of Lck, implying that CD4 signalling may involve changes in tyrosine protein phosphorylation. In this report, we describe that cross-linking of CD4 results in a series of rapid changes in intracellular tyrosine protein phosphorylation. The most prominent CD4-induced tyrosine phosphorylation change involved p56lck, which became extensively phosphorylated on the carboxy-terminal tyrosine residue 505 and, to a lesser extent, lymphocytes can transduce an intracellular signal resulting in tyrosine protein phosphorylation and strongly suggest that this property of CD4 is mediated through p56lck.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=362527Documentos Relacionados
- Cross-linking of T-cell surface molecules CD4 and CD8 stimulates phosphorylation of the lck tyrosine protein kinase at the autophosphorylation site.
- Fas (CD95) expression and death-mediating function are induced by CD4 cross-linking on CD4+ T cells.
- Cross-linking of interleukin 4 to surface molecules on murine T and B lymphocytes.
- The CD4 receptor is complexed in detergent lysates to a protein-tyrosine kinase (pp58) from human T lymphocytes.
- Upregulation of human immunodeficiency virus (HIV) replication by CD4 cross-linking in peripheral blood mononuclear cells of HIV-infected adults.