Molecular basis of AKAP specificity for PKA regulatory subunits.
Localization of cyclic AMP (cAMP)-dependent protein kinase (PKA) by A kinase-anchoring proteins (AKAPs) restricts the action of this broad specificity kinase. The high-resolution crystal structures of the docking and dimerization (D/D) domain of the RIIalpha regulatory subunit of PKA both in the apo state and in complex with the high-affinity anchoring peptide AKAP-IS explain the molecular basis for AKAP-regulatory subunit recognition. AKAP-IS folds into an amphipathic alpha helix that engages an essentially preformed shallow groove on the surface of the RII dimer D/D domains. Conserved AKAP aliphatic residues dominate interactions to RII at the predominantly hydrophobic interface, whereas polar residues are important in conferring R subunit isoform specificity. Using a peptide screening approach, we have developed SuperAKAP-IS, a peptide that is 10,000-fold more selective for the RII isoform relative to RI and can be used to assess the impact of PKA isoform-selective anchoring on cAMP-responsive events inside cells.
Gold
Matthew G
MG
Section of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, United Kingdom.
Lygren
Birgitte
B
Dokurno
Pawel
P
Hoshi
Naoto
N
McConnachie
George
G
Taskén
Kjetil
K
Carlson
Cathrine R
CR
Scott
John D
JD
Barford
David
D
D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001051:Apoenzymes / Q000378:metabolism; D001665:Binding Sites; D002417:Cattle; D018360:Crystallography, X-Ray; D054754:Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry* / Q000378:metabolism*; D019281:Dimerization; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity
D048868:Adaptor Proteins, Signal Transducing; D001051:Apoenzymes; D054754:Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit; C517819:PRKAR2A protein, human; D010455:Peptides; C517821:Prkar2a protein, mouse; D021122:Protein Subunits; D017868:Cyclic AMP-Dependent Protein Kinases