PubMed:11131153 JSONTXT

{"project":"2015-BEL-Sample","denotations":[{"id":"T1","span":{"begin":119,"end":956},"obj":"cat(p(HGNC:IL2)) increases complex(p(HGNC:LYN), p(HGNC:IL2RB))"}],"text":"IL-2 induces the association of IL-2Rbeta, lyn, and MAP kinase ERK-1 in human neutrophils.\nIL-2, first identified as a T cell growth factor, has been proven to activate many cell types including polymorphonuclear neutrophils (PMN3). However, the mechanisms involved in PMN activation, especially the signaling pathways used by the IL-2R, are currently unknown. Here we demonstrate that IL-2 has the ability to induce protein tyrosine kinases in human PMN, and we provide the first evidence that lyn kinase is activated and physically associated with MAP kinase/ERK1. Co-immunoprecipitation experiments with anti-IL-2Rbeta and Western blotting with anti-p53/56lym revealed that lyn protein was present in IL-2R precipitates and that the association of lyn with IL-2Rbeta was markedly elevated by IL-2 stimulation. Furthermore the activity of lyn kinase, evaluated by an in vitro kinase assay with enolase as a substrate, increased following IL-2 stimulation. Another important finding was that, upon IL-2 activation, MAPK/ERK1 was also phosphorylated in PMN. A direct association between lyn and ERK1 was initially demonstrated by co-immunoprecipitation/Western blotting and then definitively proven by the use of a GST-ERK1 fusion protein. We showed that ERK1 binds lyn only in IL-2 stimulated PMN, but not in unstimulated PMN. These results suggest that IL-2 can promote the association of lyn protein tyrosine kinase with IL-2Rbeta as well as the direct binding of MAPK/ERK1 to lyn. The signaling pathway utilized by human PMN in response to IL-2 may thus involve the association of lyn with IL-2Rbeta and the activation process also triggers the recruitment and activation of a specific ERK."}

{"project":"2015-BEL-Sample-2","denotations":[{"id":"BEL:20000226","span":{"begin":119,"end":956},"obj":"cat(p(HGNC:IL2)) increases kin(p(HGNC:LYN))"},{"id":"BEL:20000228","span":{"begin":119,"end":956},"obj":"cat(p(HGNC:IL2)) increases complex(p(HGNC:LYN), p(HGNC:IL2RB))"},{"id":"BEL:20000226","span":{"begin":119,"end":956},"obj":"cat(p(HGNC:IL2)) increases kin(p(HGNC:LYN))"},{"id":"BEL:20000228","span":{"begin":119,"end":956},"obj":"cat(p(HGNC:IL2)) increases complex(p(HGNC:LYN), p(HGNC:IL2RB))"},{"id":"BEL:20029946","span":{"begin":732,"end":956},"obj":"cat(p(HGNC:IL2RB)) increases kin(p(HGNC:LYN))"},{"id":"BEL:20043068","span":{"begin":732,"end":956},"obj":"p(HGNC:IL2) increases cat(p(HGNC:IL2RB))"}],"text":"IL-2 induces the association of IL-2Rbeta, lyn, and MAP kinase ERK-1 in human neutrophils.\nIL-2, first identified as a T cell growth factor, has been proven to activate many cell types including polymorphonuclear neutrophils (PMN3). However, the mechanisms involved in PMN activation, especially the signaling pathways used by the IL-2R, are currently unknown. Here we demonstrate that IL-2 has the ability to induce protein tyrosine kinases in human PMN, and we provide the first evidence that lyn kinase is activated and physically associated with MAP kinase/ERK1. Co-immunoprecipitation experiments with anti-IL-2Rbeta and Western blotting with anti-p53/56lym revealed that lyn protein was present in IL-2R precipitates and that the association of lyn with IL-2Rbeta was markedly elevated by IL-2 stimulation. Furthermore the activity of lyn kinase, evaluated by an in vitro kinase assay with enolase as a substrate, increased following IL-2 stimulation. Another important finding was that, upon IL-2 activation, MAPK/ERK1 was also phosphorylated in PMN. A direct association between lyn and ERK1 was initially demonstrated by co-immunoprecipitation/Western blotting and then definitively proven by the use of a GST-ERK1 fusion protein. We showed that ERK1 binds lyn only in IL-2 stimulated PMN, but not in unstimulated PMN. These results suggest that IL-2 can promote the association of lyn protein tyrosine kinase with IL-2Rbeta as well as the direct binding of MAPK/ERK1 to lyn. The signaling pathway utilized by human PMN in response to IL-2 may thus involve the association of lyn with IL-2Rbeta and the activation process also triggers the recruitment and activation of a specific ERK."}