biostudies-literature00460Paris LLNCRR NIH HHSNCI NIH HHSNIGMS NIH HHS39844-54https://www.ebi.ac.uk/biostudies/studies/S-EPMC3000966biostudies-literatureUnknown285(51)The Syk protein-tyrosine kinase is phosphorylated on multiple tyrosines after the aggregation of the B cell antigen receptor. However, metabolic labeling experiments indicate that Syk is inducibly phosphorylated to an even greater extent on serine after receptor ligation. A combination of phosphopeptide mapping and mass spectrometric analyses indicates that serine 291 is a major site of phosphorylation. Serine 291 lies within a 23-amino acid insert located within the linker B region that distinguishes Syk from SykB and Zap-70. The phosphorylation of serine-291 by protein kinase C enhances the ability of Syk to couple the antigen receptor to the activation of the transcription factors NFAT and Elk-1. Protein interaction studies indicate a role for the phosphorylated linker insert in promoting an interaction between Syk and the chaperone protein, prohibitin.The Journal of biological chemistryRegulation of Syk by phosphorylation on serine in the linker insert.PMC3000966CA115465S10 RR025044-01S10 RR025044CA037372R01 CA037372R01 GM088317Harrison MLOng SSHu JMa HTao WAGalan JParis LLMartin VAGeahlen RL46falseRegulation of Syk by phosphorylation on serine in the linker insert.The Syk protein-tyrosine kinase is phosphorylated on multiple tyrosines after the aggregation of the B cell antigen receptor. However, metabolic labeling experiments indicate that Syk is inducibly phosphorylated to an even greater extent on serine after receptor ligation. A combination of phosphopeptide mapping and mass spectrometric analyses indicates that serine 291 is a major site of phosphorylation. Serine 291 lies within a 23-amino acid insert located within the linker B region that distinguishes Syk from SykB and Zap-70. The phosphorylation of serine-291 by protein kinase C enhances the ability of Syk to couple the antigen receptor to the activation of the transcription factors NFAT and Elk-1. Protein interaction studies indicate a role for the phosphorylated linker insert in promoting an interaction between Syk and the chaperone protein, prohibitin.2010-01-01T00:00:00Z2010 Dec2022-02-09T10:27:25.931Z2019-03-27T00:37:20ZS-EPMC30009662095653710.1074/jbc.m110.16450910.1074/jbc.M110.164509