title: Suborganelle sensing of mitochondrial cAMP-dependent protein kinase activity.
abstract: A fluorescent sensor of protein kinase activity has been developed and used to characterize the compartmentalized location of cAMP-dependent protein kinase activity in mitochondria. The sensor functions via a phosphorylation-induced release of a quencher from a peptide-based substrate, producing a 150-fold enhancement in fluorescence. The quenching phenomenon transpires via interaction of the quencher with Arg residues positioned on the peptide substrate. Although the cAMP-dependent protein kinase is known to be present in mitochondria, the relative amount of enzyme positioned in the major compartments (outer membrane, intermembrane space, and the matrix) of the organelle is unclear. The fluorescent sensor developed in this study was used to reveal the relative matrix/intermembrane space/outer membrane (85:6:9) distribution of PKA in bovine heart mitochondria.
authors.affiliation: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Agnes
authors.forename: Finith
authors.initials: F
authors.lastname: Jernigan
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Shell
authors.forename: Vyas
authors.initials: V
authors.lastname: Sharma
authors.forename: David S
authors.initials: DS
authors.lastname: Lawrence
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002417:Cattle; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry*; D005453:Fluorescence; D006801:Humans; D008929:Mitochondria, Heart / Q000201:enzymology*
chemical_list: D017868:Cyclic AMP-Dependent Protein Kinases