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Dual role of the tyrosine activation motif of the Ig-alpha protein during signal transduction via the B cell antigen receptor.

1994; Springer Nature; Volume: 13; Issue: 1 Linguagem: Inglês

10.1002/j.1460-2075.1994.tb06237.x

1460-2075

Heinrich Flaswinkel, Michael Reth,

Immune Cell Function and Interaction

Research Article1 January 1994free access Dual role of the tyrosine activation motif of the Ig-alpha protein during signal transduction via the B cell antigen receptor. H. Flaswinkel H. Flaswinkel Max-Planck-Institut für Immunobiologie, Freiburg, Germany. Search for more papers by this author M. Reth M. Reth Max-Planck-Institut für Immunobiologie, Freiburg, Germany. Search for more papers by this author H. Flaswinkel H. Flaswinkel Max-Planck-Institut für Immunobiologie, Freiburg, Germany. Search for more papers by this author M. Reth M. Reth Max-Planck-Institut für Immunobiologie, Freiburg, Germany. Search for more papers by this author Author Information H. Flaswinkel1 and M. Reth1 1Max-Planck-Institut für Immunobiologie, Freiburg, Germany. The EMBO Journal (1994)13:83-89https://doi.org/10.1002/j.1460-2075.1994.tb06237.x PDFDownload PDF of article text and main figures. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info The B cell antigen receptor (BCR) is a multimeric protein complex consisting of the ligand binding immunoglobulin molecule and the Ig-alpha/beta heterodimer that mediates intracellular signalling by coupling the receptor to protein tyrosine kinases (PTKs). Transfection of the Ig-alpha deficient myeloma cell line J558L microns with expression vectors coding for mutated Ig-alpha allowed us to test the function of the tyrosines in the cytoplasmic region of Ig-alpha in the context of the BCR. Furthermore we expressed Ig-alpha mutations as chimeric CD8-Ig-alpha molecules on K46 B lymphoma cells and tested their signalling capacity in terms of PTK activation and release of calcium. We show here that the conserved tyrosine residues in the cytoplasmic portion of Ig-alpha have a dual role. First, they are required for efficient activation of PTKs during signal induction and second, one of them is subject to phosphorylation by activated src-related PTKs. Phosphorylation on tyrosine in the cytoplasmic portion of Ig-alpha is discussed as a possible mechanism to couple the BCR to SH2 domain-carrying molecules. Previous ArticleNext Article Volume 13Issue 11 January 1994In this issue RelatedDetailsLoading ...