Altering the specificity of signal transduction cascades: positive regulation of c-Jun transcriptional activity by protein kinase A.

摘要: Protein phosphorylation is commonly used to modulate transcription factor activity. However, all existing genetic evidence for stimulation of activity by rests on loss-of-function mutations. To demonstrate conclusively that a potentiates its transactivation potential in vivo, we constructed c-Jun mutant phosphorylated the cAMP-sensitive protein kinase A (PKA) instead UV- and Ras-responsive JNK. The transcriptional this enhanced PKA, but not JNK activation. These results provide positive conclusive proof critical site (Ser73) located activation domain directly responsible enhancing function.