A Fluorescent Reporter of the Phosphorylation Status of the Substrate Protein STAT3


  • We thank Dr. Tony Hunter for helpful discussions. L.W. thanks the support from the Salk Innovation grant, March of Dimes Foundation (5-FY08-110), CIRM (RN1-00577-1), NCI (P30CA014195) and NIH (1DP2OD004744).


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Roving reporter: A reversible biosensor reports the phosphorylation status of full-length substrate protein STAT3 by genetically incorporating 7-hydroxycoumarin into its phosphotyrosine binding pocket (see picture). A large fluorescence increase with characteristic emission and excitation properties results as a response to phosphorylation of STAT3 in vitro and endogenously in nuclear extracts.