Delineation of type I protein kinase A-selective signaling events using an RI anchoring disruptor.
Control of specificity in cAMP signaling is achieved by A-kinase anchoring proteins (AKAPs), which assemble cAMP effectors such as protein kinase A (PKA) into multiprotein signaling complexes in the cell. AKAPs tether the PKA holoenzymes at subcellular locations to favor the phosphorylation of selected substrates. PKA anchoring is mediated by an amphipathic helix of 14-18 residues on each AKAP that binds to the R subunit dimer of the PKA holoenzymes. Using a combination of bioinformatics and peptide array screening, we have developed a high affinity-binding peptide called RIAD (RI anchoring disruptor) with >1000-fold selectivity for type I PKA over type II PKA. Cell-soluble RIAD selectively uncouples cAMP-mediated inhibition of T cell function and inhibits progesterone synthesis at the mitochondria in steroid-producing cells. This study suggests that these processes are controlled by the type I PKA holoenzyme and that RIAD can be used as a tool to define anchored type I PKA signaling events.
Carlson
Cathrine Rein
CR
Biotechnology Centre of Oslo, University of Oslo, PB 1125 Blindern, N-0317, Oslo, Norway; Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239. Electronic address: cathrine.carlson@biotek.uio.no.
Lygren
Birgitte
B
Biotechnology Centre of Oslo, University of Oslo, PB 1125 Blindern, N-0317, Oslo, Norway; Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239.
Berge
Torunn
T
Biotechnology Centre of Oslo, University of Oslo, PB 1125 Blindern, N-0317, Oslo, Norway.
Hoshi
Naoto
N
Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239.
Wong
Wei
W
Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239.
Taskén
Kjetil
K
Biotechnology Centre of Oslo, University of Oslo, PB 1125 Blindern, N-0317, Oslo, Norway.
Scott
John D
JD
Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239.
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry*; D020035:Holoenzymes / Q000737:chemistry; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism
D020035:Holoenzymes; D010455:Peptides; D000242:Cyclic AMP; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases