Functional coupling of the src-family protein tyrosine kinases p59fyn and p53/56lyn with the interleukin 2 receptor: implications for redundancy and pleiotropism in cytokine signal transduction.

AUTOR(ES)

Kobayashi, N

RESUMO

The binding of interleukin 2 (IL-2) to the IL-2 receptor (IL-2R) induces a rapid increase in tyrosine phosphorylation of cellular proteins. In a previous study, we have shown that p56lck (lck), a src-family protein tyrosine kinase (src-PTK), physically and functionally associates with the IL-2R beta chain (IL-2R beta). To further investigate a role of src-PTKs in IL-2 signaling, we analyzed a mouse pro-B-cell line, in which lck is not expressed detectably. We observed that in this cell line, IL-2 induces activation of at least two src-PTKs, p59fyn (fyn) and p53/56lyn (lyn). Interestingly, stimulation of this cell line with IL-3 also induces activation of src-PTKs. The activation of fyn or lyn seems to be selective for stimulation with IL-2 or IL-3 since stimulation with IL-6 fails to activate them. Furthermore, we provide evidence for the physical association of fyn with IL-2R beta. Taken together with previous results, our current study suggests that different src-PTKs, each of which is expressed in a cell-type-specific manner, can participate in the IL-2 signal transduction.

Documentos Relacionados

• Human spleen tyrosine kinase p72Syk associates with the Src-family kinase p53/56Lyn and a 120-kDa phosphoprotein.
• Distinct p53/56lyn and p59fyn domains associate with nonphosphorylated and phosphorylated Ig-alpha.
• Aggregation of the high-affinity IgE receptor and enhanced activity of p53/56lyn protein-tyrosine kinase.
• Invasion of Human Epithelial Cells by Pseudomonas aeruginosa Involves Src-Like Tyrosine Kinases p60Src and p59Fyn
• The Cbl Proto-Oncogene Product Negatively Regulates the Src-Family Tyrosine Kinase Fyn by Enhancing Its Degradation