Mechanism of A-kinase-anchoring protein 79 (AKAP79) and protein kinase C interaction.
The A-kinase-anchoring protein AKAP79 co-ordinates the location of cAMP-dependent protein kinase, phosphatase 2B (PP2B/calcineurin) and protein kinase C (PKC) at postsynaptic sites in neurons. In this report we focus on the mechanism of interaction between AKAP79 and PKC. We show that neither lipid activators nor kinase activation are required for association with AKAP79. The anchoring protein binds and inhibits the conserved catalytic core of PKCbetaII. AKAP79 also associates with conventional, novel and atypical isoforms of PKC in vitro and in vivo, and immunofluorescence staining of rat hippocampal neurons demonstrates that the murine anchoring-protein homologue AKAP150 is co-distributed with PKCalpha/beta, PKCepsilon or PKCiota. Binding of the AKAP79(31-52) peptide, which inhibits kinase activity, exposes the pseudosubstrate domain of PKCbetaII, allowing endoproteinase Arg-C proteolysis in the absence of kinase activators. Reciprocal experiments have identified two arginine residues at positions 39 and 40 that are essential for AKAP79(31-52) peptide inhibition of PKCbetaII. Likewise, the same mutations in the full-length anchoring protein reduced inhibition of PKCbetaII. Thus AKAP79 associates with multiple PKC isoforms through a mechanism involving protein-protein interactions at the catalytic core where binding of the anchoring protein inhibits kinase activity through displacement of the pseudosubstrate.
Faux
M C
MC
Howard Hughes Medical Institute, Vollum Institute, L474, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97201, USA.
Rollins
E N
EN
Edwards
A S
AS
Langeberg
L K
LK
Newton
A C
AC
Scott
J D
JD
D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008055:Lipids / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation / Q000235:genetics; D009474:Neurons / Q000201:enzymology / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D012697:Serine Endopeptidases / Q000378:metabolism
D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing; C415703:Akap5 protein, rat; D002352:Carrier Proteins; D007527:Isoenzymes; D008055:Lipids; D010446:Peptide Fragments; D001120:Arginine; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; C044499:submandibular proteinase A; D012697:Serine Endopeptidases