A Live-Cell Imaging Assay for Nuclear Entry of cAMP-Dependent Protein Kinase Catalytic Subunits Stimulated by Endogenous GPCR Activation.

Nuclear entry of cAMP-dependent protein kinase catalytic subunits is typically inferred from changes in net protein amount or kinase activity in the nucleus. Previous methods to directly assess nuclear entry require kinase subunit overexpression and/or supraphysiological cAMP elevation. We describe a method to detect nuclear entry of catalytic subunits expressed at an endogenous level in living cells, stimulated by cAMP in a physiological range, and in real time.