title: Atrial natriuretic peptide induces natriuretic peptide receptor-cGMP-dependent protein kinase interaction.
abstract: Circulating natriuretic peptides such as atrial natriuretic peptide (ANP) counterbalance the effects of hypertension and inhibit cardiac hypertrophy by activating cGMP-dependent protein kinase (PKG). Natriuretic peptide binding to type I receptors (NPRA and NPRB) activates their intrinsic guanylyl cyclase activity, resulting in a rapid increase in cytosolic cGMP that subsequently activates PKG. Phosphorylation of the receptor by an unknown serine/threonine kinase is required before ligand binding can activate the cyclase. While searching for downstream PKG partners using a yeast two-hybrid screen of a human heart cDNA library, we unexpectedly found an upstream association with NPRA. PKG is a serine/threonine kinase capable of phosphorylating NPRA in vitro; however, regulation of NPRA by PKG has not been previously reported. Here we show that PKG is recruited to the plasma membrane following ANP treatment, an effect that can be blocked by pharmacological inhibition of PKG activation. Furthermore, PKG participates in a ligand-dependent gain-of-function loop that significantly increases the intrinsic cyclase activity of the receptor. PKG translocation is ANP-dependent but not nitric oxide-dependent. Our results suggest that anchoring of PKG to NPRA is a key event after ligand binding that determines distal effects. As such, the NPRA-PKG association may represent a novel mechanism for compartmentation of cGMP-mediated signaling and regulation of receptor sensitivity.
authors.affiliation: Department of Pediatrics and the Heart Research Center, Oregon Health and Science University, Portland, Oregon 97239, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Airhart
authors.forename: Yong-Feng
authors.initials: YF
authors.lastname: Yang
authors.forename: Charles T
authors.initials: CT
authors.lastname: Roberts
authors.forename: Michael
authors.initials: M
authors.lastname: Silberbach
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000737:chemistry* / Q000494:pharmacology*; D001665:Binding Sites; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D015723:Gene Library; D005947:Glucose / Q000378:metabolism; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008024:Ligands; D008856:Microscopy, Fluorescence; D009206:Myocardium / Q000378:metabolism; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D021381:Protein Transport; D051381:Rats; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D018000:Receptors, Peptide / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D013696:Temperature; D013997:Time Factors; D014162:Transfection; D020798:Two-Hybrid System Techniques
chemical_list: D018076:DNA, Complementary; D008024:Ligands; D018000:Receptors, Peptide; D011994:Recombinant Proteins; D009569:Nitric Oxide; D009320:Atrial Natriuretic Factor; D017869:Cyclic GMP-Dependent Protein Kinases; D006162:Guanylate Cyclase; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D006152:Cyclic GMP; D005947:Glucose