Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Human T cells can be activated and induced to proliferate through either the antigen-specific receptor complex (TcR-CD3) or the CD2 surface molecule. Following stimulation, both serine and tyrosine phosphorylation of cellular protein have been demonstrated to occur. p56lck, a protein tyrosine kinase associated to the inner face of the plasma membrane, is almost exclusively expressed in lymphoid cells, especially T cells. Within minutes after activation of a human T cell-derived line (Jurkat) via stimulation of either the TcR-CD3 complex or the CD2 glycoprotein, we observed a hyperphorphosylation of p56lck. A concomitant shift to a higher molecular weight in sodium dodecyl sulfate-polyacrylamide gel was also observed. Similar changes were obtained with phorbol 12-myristate 13-acetate. Tryptic phosphopeptide analysis of the hyperphosphorylated form of p56lck yielded new phosphorylated sites in serine residues and an increased tyrosine phosphorylation. These results suggest that p56lck may be intimately connected to the signaling pathway in T cell activation.

Original publication




Journal article


Eur J Immunol

Publication Date





2183 - 2189


Antigens, Differentiation, T-Lymphocyte, Blotting, Western, CD2 Antigens, Humans, In Vitro Techniques, Lymphocyte Activation, Lymphocyte Specific Protein Tyrosine Kinase p56(lck), Molecular Weight, Peptide Fragments, Phosphorylation, Phosphoserine, Phosphotyrosine, Protein-Tyrosine Kinases, Receptors, Antigen, T-Cell, Receptors, Immunologic, T-Lymphocytes, Time Factors, Tyrosine