English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Amplification of B cell antigen receptor signaling by a Syk/ITAM positive feedback loop

MPS-Authors
/persons/resource/persons191292

Rolli,  Véronique
Research Group and Chair of Molecular Immunology of the University of Freiburg, Max Planck Institute of Immunobiology and Epigenetics, Max Planck Society;

/persons/resource/persons191065

Gallwitz,  Maike
Research Group and Chair of Molecular Immunology of the University of Freiburg, Max Planck Institute of Immunobiology and Epigenetics, Max Planck Society;

/persons/resource/persons198885

Wossning,  Thomas
Research Group and Chair of Molecular Immunology of the University of Freiburg, Max Planck Institute of Immunobiology and Epigenetics, Max Planck Society;

/persons/resource/persons198880

Flemming,  Alexandra
Research Group and Chair of Molecular Immunology of the University of Freiburg, Max Planck Institute of Immunobiology and Epigenetics, Max Planck Society;

/persons/resource/persons191299

Schamel,  Wolfgang W. A.
Research Group and Chair of Molecular Immunology of the University of Freiburg, Max Planck Institute of Immunobiology and Epigenetics, Max Planck Society;

/persons/resource/persons191285

Reth,  Michael
Research Group and Chair of Molecular Immunology of the University of Freiburg, Max Planck Institute of Immunobiology and Epigenetics, Max Planck Society;

External Resource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Rolli, V., Gallwitz, M., Wossning, T., Flemming, A., Schamel, W. W. A., Zurn, C., et al. (2002). Amplification of B cell antigen receptor signaling by a Syk/ITAM positive feedback loop. Molecular Cell, 10(5), 1057-1069.


Cite as: http://hdl.handle.net/11858/00-001M-0000-002B-95F7-F
Abstract
We have established a protocol allowing transient and inducible coexpression of many foreign genes in Drosophila S2 Schneider cells. With this powerful approach of reverse genetics, we studied the interaction of the protein tyrosine kinases Syk and Lyn with the B cell antigen receptor (BCR). We find that Lyn phosphorylates only the first tyrosine whereas Syk phosphorylates both tyrosines of the BCR immunoreceptor tyrosine-based activation motif (ITAM). Furthermore, we show that Syk is a positive allosteric enzyme, which is strongly activated by the binding to the phosphorylated ITAM tyrosines, thus initiating a positive feedback loop at the receptor. The BCR-dependent Syk activation and signal amplification is efficiently counterbalanced by protein tyrosine phosphatases, the activity of which is regulated by H2O2 and the redox equilibrium inside the cell.