Syk inhibits the activity of protein kinase a by phosphorylating tyrosine 330 of the catalytic subunit

Abstract

Background: Syk is a tyrosine kinase with both tumor promoting and tumor suppressing activities in cancer cells. Results: Protein kinase A is phosphorylated on a C-terminal tyrosine by Syk. Conclusion: The phosphorylation of PKA inhibits its activity and its ability to activate CREB. Significance: The phosphorylation by Syk of PKA inhibits its participation in downstream signaling pathways. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.