Identification of cGMP-dependent protein kinase anchoring proteins (GKAPs).
To promote both efficiency and selectivity, many protein kinases and phosphatases are maintained in specific subcellular microenvironments through their association with anchoring proteins. In this study, we describe a new class of proteins, called GKAPS, that specifically bind the Type II cGMP-dependent protein kinase (PKG). GKAPs were detected in rat aorta, brain, and intestine using a protein overlay technique. The PKG binding proteins were distinct from AKAPs, proteins known to bind the cAMP-dependent protein kinase (PKA). Furthermore, a synthetic peptide that blocks association of PKA with AKAPs did not affect the PKG-GKAP interaction. Deletion mutagenesis was used to map the GKAP binding determinants within PKG to the N-terminal regulatory region. While most GKAPs were tissue-specific, a ubiquitous PKG-binding protein was detected and identified as myosin. Analysis of myosin fragments revealed that PKG binds within Subfragment 2. The results define a novel class of anchoring proteins that may target PKG for specific functional roles.
Vo
N K
NK
Neurological Sciences Institute, Oregon Health Sciences University, Portland 97209, USA.
Gettemy
J M
JM
Coghlan
V M
VM
D000818:Animals; D001011:Aorta / Q000737:chemistry; D001665:Binding Sites; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D004252:DNA Mutational Analysis; D007422:Intestines / Q000737:chemistry; D008958:Models, Molecular; D009218:Myosins / Q000302:isolation & purification / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D011485:Protein Binding; D051381:Rats; D000074407:SAP90-PSD95 Associated Proteins; D017384:Sequence Deletion; D014018:Tissue Distribution
D002352:Carrier Proteins; D009419:Nerve Tissue Proteins; D000074407:SAP90-PSD95 Associated Proteins; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D009218:Myosins