The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Interleukin 2 regulates Raf-1 kinase activity through a tyrosine phosphorylation-dependent mechanism in a T-cell line.

Previously we found that interleukin 2 (IL-2) induces tyrosine phosphorylation and activation of the serine/threonine-specific kinase encoded by the raf-1 protooncogene in a T-cell line, CTLL-2. Here we extended these findings by exploring the effects of selective removal of phosphate from tyrosines in p72-74-Raf-1 kinase that had been immunoprecipitated from IL-2-stimulated CTLL-2 cells. Treatment in vitro of IL-2- activated Raf-1 with the tyrosine-specific phosphatases CD45 and TCPTP (formerly called T-cell protein tyrosine phosphatase) reduced Raf kinase activity to nearly baseline levels. This effect was completely inhibited by the phosphatase inhibitor sodium orthovanadate. In contrast, treatment of Raf-1 with a serine/threonine-specific phosphatase, protein phosphatase 1 ( PP-1), resulted in a more modest decrease in Raf in vitro kinase activity, and this effect was prevented by okadaic acid. Two-dimensional phosphoamino acid analysis confirmed the selective removal of phosphate from tyrosine by CD45 and from serine and threonine by PP-1. The immunoreactivity of p72-74-Raf-1 with anti-phosphotyrosine antibodies was also completely abolished by treatment with CD45 in the absence but not in the presence of sodium orthovanadate. These findings provide evidence that the IL-2- stimulated phosphorylation of Raf-1 on tyrosines plays an important role in upregulating the activity of this serine/threonine-specific kinase in CTLL-2 cells and, as such, provides a model system for studying the transfer of growth factor-initiated signals from protein tyrosine kinases to serine/threonine-specific kinases.[1]

References

  1. Interleukin 2 regulates Raf-1 kinase activity through a tyrosine phosphorylation-dependent mechanism in a T-cell line. Turner, B.C., Tonks, N.K., Rapp, U.R., Reed, J.C. Proc. Natl. Acad. Sci. U.S.A. (1993) [Pubmed]
 
WikiGenes - Universities