The Experts below are selected from a list of 2199 Experts worldwide ranked by ideXlab platform
Lincoln R. Potter - One of the best experts on this subject based on the ideXlab platform.
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insulin degrading enzyme modulates the Natriuretic Peptide mediated signaling response
Journal of Biological Chemistry, 2011Co-Authors: Luis A Ralat, Lincoln R. Potter, Min Ren, Qing Guo, Todd Funke, Deborah M Dickey, Weijen TangAbstract:Natriuretic Peptides (NPs) are cyclic vasoactive Peptide hormones with high therapeutic potential. Three distinct NPs (ANP, BNP, and CNP) can selectively activate Natriuretic Peptide Receptors, NPR-A and NPR-B, raising the cyclic GMP (cGMP) levels. Insulin-degrading enzyme (IDE) was found to rapidly cleave ANP, but the functional consequences of such cleavages in the cellular environment and the molecular mechanism of recognition and cleavage remain unknown. Here, we show that reducing expression levels of IDE profoundly alters the response of NPR-A and NPR-B to the stimulation of ANP, BNP, and CNP in cultured cells. IDE rapidly cleaves ANP and CNP, thus inactivating their ability to raise intracellular cGMP. Conversely, reduced IDE expression enhances the stimulation of NPR-A and NPR-B by ANP and CNP, respectively. Instead of proteolytic inactivation, IDE cleavage can lead to hyperactivation of BNP toward NPR-A. Conversely, decreasing IDE expression reduces BNP-mediated signaling. Additionally, the cleavages of ANP and BNP by IDE render them active with NPR-B and a reduction of IDE expression diminishes the ability of ANP and BNP to stimulate NPR-B. Our kinetic and crystallographic analyses offer the molecular basis for the selective degradation of NPs and their variants by IDE. Furthermore, our studies reveal how IDE utilizes its catalytic chamber and exosite to engulf and bind up to two NPs leading to biased stochastic, non-sequential cleavages and the ability of IDE to switch its substrate selectivity. Thus, the evolutionarily conserved IDE may play a key role in modulating and reshaping the strength and duration of NP-mediated signaling.
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Determination of new phosphorylation sites within Natriuretic Peptide Receptors using mass spectrometric methods
BMC Pharmacology, 2009Co-Authors: Andrea R. Yoder, Timothy J Griffin, Matthew D. Stone, Lincoln R. PotterAbstract:Background While it has long been know that phosphorylation of the kinase homology domain is a key regulatory mechanism of Natriuretic Peptide Receptors, no biochemical proof for individual phosphorylation sites has been reported. Here, we describe biochemical verification of previously identified phosphorylation sites in both Natriuretic Peptide receptor A (NPR-A) and Natriuretic Peptide receptor B (NPR-B) as well as the identification of novel phosphorylation sites in both Receptors.
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adenine nucleotides decrease the apparent km of endogenous Natriuretic Peptide Receptors for gtp
American Journal of Physiology-endocrinology and Metabolism, 2007Co-Authors: Laura K. Antos, Lincoln R. PotterAbstract:Natriuretic Peptide Receptors A (NPR-A) and B (NPR-B) mediate most effects of Natriuretic Peptides by synthesizing cGMP. ATP increases the activity of these Receptors by an unknown mechanism. We re...
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Natriuretic Peptides their Receptors and cyclic guanosine monophosphate dependent signaling functions
Endocrine Reviews, 2006Co-Authors: Lincoln R. Potter, Sarah E Abbeyhosch, Deborah M DickeyAbstract:Natriuretic Peptides are a family of structurally related but genetically distinct hormones/paracrine factors that regulate blood volume, blood pressure, ventricular hypertrophy, pulmonary hypertension, fat metabolism, and long bone growth. The mammalian members are atrial Natriuretic Peptide, B-type Natriuretic Peptide, C-type Natriuretic Peptide, and possibly osteocrin/musclin. Three single membrane-spanning Natriuretic Peptide Receptors (NPRs) have been identified. Two, NPR-A/GC-A/NPR1 and NPR-B/GC-B/NPR2, are transmembrane guanylyl cyclases, enzymes that catalyze the synthesis of cGMP. One, NPR-C/NPR3, lacks intrinsic enzymatic activity and controls the local concentrations of Natriuretic Peptides through constitutive receptor-mediated internalization and degradation. Single allele-inactivating mutations in the promoter of human NPR-A are associated with hypertension and heart failure, whereas homozygous inactivating mutations in human NPR-B cause a form of short-limbed dwarfism known as acromesomelic...
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atp independent activation of Natriuretic Peptide Receptors
BMC Pharmacology, 2005Co-Authors: Laura K. Antos, Darcy R. Flora, Sarah E Abbeyhosch, Lincoln R. PotterAbstract:Natriuretic Peptide receptor A (NPR-A) is an essential cardiovascular regulator that is stimulated by atrial Natriuretic Peptide and brain Natriuretic Peptide, whereas Natriuretic Peptide receptor B (NPR-B) stimulates long bone growth in a C-type Natriuretic Peptide-dependent manner. Many reports indicate that ATP is essential for NPR-A and NPR-B activation. Current models suggest that Natriuretic Peptide binding to receptor extracellular domains causes ATP binding to intracellular kinase homology domains, which derepresses adjacent catalytic domains. Here, we report 100-fold activation of Natriuretic Peptide Receptors in the absence of ATP. Addition of a nonhydrolyzable ATP analog had no effect at early time periods (seconds) but increased cGMP production about two-fold after longer incubations (minutes), consistent with a stabilization, not activation, mechanism. These data indicate that ATP does not activate Natriuretic Peptide Receptors. Instead, ATP increases activity primarily by maintaining proper receptor phosphorylation status, but also serves a previously unappreciated enzyme stabilizing function. from 2nd International Conference of cGMP Generators, Effectors and Therapeutic Implications Potsdam, Germany, 10–12 June, 2005
David H Evans - One of the best experts on this subject based on the ideXlab platform.
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vasoactive Receptors in abdominal blood vessels of the dogfish shark squalus acanthias
Physiological and Biochemical Zoology, 2001Co-Authors: David H EvansAbstract:Abstract Previous studies have demonstrated that the ventral aorta of the dogfish shark, Squalus acanthias, responds to a variety of cell‐signaling agents. To investigate the generality of vasoactive Receptors in the shark vasculature, in particular a conductance artery (anterior mesenteric) and vein (posterior intestinal), I measured the effect of acetylcholine, endothelin, nitric oxide, Natriuretic Peptides, and prostaglandins on tension in isolated rings from these vessels. Both vessels responded to these agents, and responses to receptor‐specific ligands for endothelin and Natriuretic Peptide Receptors suggest that B‐type endothelin Receptors are expressed in both vessels and that the artery expresses both A‐ and B‐type Natriuretic Peptide Receptors; however, the vein (like the ventral aorta) expresses only the B‐type Natriuretic Peptide receptor. My data suggest that a suite of signaling systems is ubiquitous in both arteries and veins in at least this elasmobranch species. Their role in hemodynamics...
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Natriuretic Peptide Receptors in the kidney and the ventral and dorsal aortae of the atlantic hagfish myxine glutinosa agnatha
The Journal of Experimental Biology, 1995Co-Authors: Tes Toop, John A Donald, David H EvansAbstract:The character of Natriuretic Peptide Receptors (NPRs) in the kidney and aortae of the Atlantic hagfish Myxine glutinosa was determined and compared with that of NPRs in hagfish gills. The relationship of hagfish kidney and aortic NPRs with NPRs from higher vertebrates was also examined. Iodinated atrial and C-type Natriuretic Peptides (NPs) (125I-ANP, 125I-CNP) were used in tissue section autoradiography, competition studies and guanylate cyclase (GC) assays. Rat atrial and porcine C-type NPs (rANP, pCNP) and rat des[Gln18, Ser19, Gly20, Leu21 Gly22]ANP-(4-23)-NH2 (C-ANF, which binds to the mammalian and teleost 'clearance' receptor, NPR-C), were used as competing ligands. 125I-ANP binding sites were observed on both aortae and on the glomeruli, neck segments and archinephric ducts of the kidney. 4.0 nmol l-1 rANP competed for 50% of 125I-ANP glomerular sites. 125I-CNP did not visibly bind to any of the tissues, but 300 nmol l-1 pCNP competed for 50% of 125I-ANP glomerular sites. C-ANF failed to compete for 125I-ANP sites. rANP and pCNP stimulated cyclic GMP production in kidney membrane preparations, but C-ANF did not, demonstrating that the hagfish kidney NPR is GC-linked. This study suggests that a predominant population of ANP-like Receptors, similar to the mammalian NPR-A, exists in the myxinoid aortae and kidney tissue. However, no detectable population of a receptor that binds all NPs, such as is present in the hagfish gill, nor an NPR similar to the NPR-C of higher vertebrates was discovered.
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localisation and characteristics of Natriuretic Peptide Receptors in the gills of the atlantic hagfish myxine glutinosa agnatha
The Journal of Experimental Biology, 1995Co-Authors: Tes Toop, John A Donald, David H EvansAbstract:Specific binding of iodinated Natriuretic Peptides 125I-ANP and 125I-CNP was examined in the gill of the Atlantic hagfish Myxine glutinosa by tissue section autoradiography, saturation and competition analysis of binding to membrane preparations, affinity cross-linking, followed by SDS-PAGE and guanylate cyclase assays. Autoradiographs showed specific, saturable binding on the respiratory lamellar epithelium. In vitro analysis of the binding sites demonstrated that 125I-ANP bound to two receptor sites with the same affinity (Kd = 15.4 +/- 1.6 pmol l-1; Bmax = 45.9 +/- 3.0 fmol mg-1 protein). 125I-CNP bound to high- and low-affinity receptor sites; variables for the high-affinity site (Kd = 12.9 +/- 4.7 pmol l-1; Bmax = 23.4 +/- 6.5 fmol mg-1 protein) did not differ from those for the 125I-ANP sites. The low-affinity site had an apparent Kd and Bmax of 380 +/- 80 pmol l-1 and 120 +/- 21 fmol mg-1 protein, respectively. All Receptors had an apparent molecular mass of approximately 150 kDa, with no indication of a mammalian type NPR-C at a lower apparent molecular mass. 1 nmol l-1 unlabelled rANP and 20 and 30 nmol l-1 unlabelled pCNP and C-ANF, respectively, competed for 50% of 125I-ANP sites. 0.1 nmol l-1 rANP and pCNP and 8 nmol l-1 C-ANF competitively inhibited 50% of 125I-CNP binding. Both rANP and pCNP stimulated cyclic GMP production, although rANP was a more potent stimulator than was pCNP. C-ANF did not stimulate cyclic GMP production. These data suggest the existence of an ANP guanylate-cyclase-linked receptor similar to the mammalian NPR-A and an ANP/CNP receptor that may be similar to, although not structurally homologous with, the mammalian NPR-C clearance receptor.
Tes Toop - One of the best experts on this subject based on the ideXlab platform.
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Natriuretic Peptide Receptors in the kidney and the ventral and dorsal aortae of the atlantic hagfish myxine glutinosa agnatha
The Journal of Experimental Biology, 1995Co-Authors: Tes Toop, John A Donald, David H EvansAbstract:The character of Natriuretic Peptide Receptors (NPRs) in the kidney and aortae of the Atlantic hagfish Myxine glutinosa was determined and compared with that of NPRs in hagfish gills. The relationship of hagfish kidney and aortic NPRs with NPRs from higher vertebrates was also examined. Iodinated atrial and C-type Natriuretic Peptides (NPs) (125I-ANP, 125I-CNP) were used in tissue section autoradiography, competition studies and guanylate cyclase (GC) assays. Rat atrial and porcine C-type NPs (rANP, pCNP) and rat des[Gln18, Ser19, Gly20, Leu21 Gly22]ANP-(4-23)-NH2 (C-ANF, which binds to the mammalian and teleost 'clearance' receptor, NPR-C), were used as competing ligands. 125I-ANP binding sites were observed on both aortae and on the glomeruli, neck segments and archinephric ducts of the kidney. 4.0 nmol l-1 rANP competed for 50% of 125I-ANP glomerular sites. 125I-CNP did not visibly bind to any of the tissues, but 300 nmol l-1 pCNP competed for 50% of 125I-ANP glomerular sites. C-ANF failed to compete for 125I-ANP sites. rANP and pCNP stimulated cyclic GMP production in kidney membrane preparations, but C-ANF did not, demonstrating that the hagfish kidney NPR is GC-linked. This study suggests that a predominant population of ANP-like Receptors, similar to the mammalian NPR-A, exists in the myxinoid aortae and kidney tissue. However, no detectable population of a receptor that binds all NPs, such as is present in the hagfish gill, nor an NPR similar to the NPR-C of higher vertebrates was discovered.
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localisation and characteristics of Natriuretic Peptide Receptors in the gills of the atlantic hagfish myxine glutinosa agnatha
The Journal of Experimental Biology, 1995Co-Authors: Tes Toop, John A Donald, David H EvansAbstract:Specific binding of iodinated Natriuretic Peptides 125I-ANP and 125I-CNP was examined in the gill of the Atlantic hagfish Myxine glutinosa by tissue section autoradiography, saturation and competition analysis of binding to membrane preparations, affinity cross-linking, followed by SDS-PAGE and guanylate cyclase assays. Autoradiographs showed specific, saturable binding on the respiratory lamellar epithelium. In vitro analysis of the binding sites demonstrated that 125I-ANP bound to two receptor sites with the same affinity (Kd = 15.4 +/- 1.6 pmol l-1; Bmax = 45.9 +/- 3.0 fmol mg-1 protein). 125I-CNP bound to high- and low-affinity receptor sites; variables for the high-affinity site (Kd = 12.9 +/- 4.7 pmol l-1; Bmax = 23.4 +/- 6.5 fmol mg-1 protein) did not differ from those for the 125I-ANP sites. The low-affinity site had an apparent Kd and Bmax of 380 +/- 80 pmol l-1 and 120 +/- 21 fmol mg-1 protein, respectively. All Receptors had an apparent molecular mass of approximately 150 kDa, with no indication of a mammalian type NPR-C at a lower apparent molecular mass. 1 nmol l-1 unlabelled rANP and 20 and 30 nmol l-1 unlabelled pCNP and C-ANF, respectively, competed for 50% of 125I-ANP sites. 0.1 nmol l-1 rANP and pCNP and 8 nmol l-1 C-ANF competitively inhibited 50% of 125I-CNP binding. Both rANP and pCNP stimulated cyclic GMP production, although rANP was a more potent stimulator than was pCNP. C-ANF did not stimulate cyclic GMP production. These data suggest the existence of an ANP guanylate-cyclase-linked receptor similar to the mammalian NPR-A and an ANP/CNP receptor that may be similar to, although not structurally homologous with, the mammalian NPR-C clearance receptor.
Tony Hunter - One of the best experts on this subject based on the ideXlab platform.
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identification and characterization of the phosphorylation sites of the guanylyl cyclase linked Natriuretic Peptide Receptors a and b
Methods, 1999Co-Authors: Lincoln R. Potter, Tony HunterAbstract:The binding of atrial Natriuretic Peptide and C-type Natriuretic Peptide to the guanylyl cyclase-linked Natriuretic Peptide Receptors A and B (NPR-A and NPR-B), respectively, results in decreases in extracellular volume, vascular tension and cell proliferation. Both NPR-A and NPR-B are extensively phosphorylated in resting cells and receptor dephosphorylation is correlated with ligand-induced homologous desensitization. To understand the role of phosphorylation in the regulation of these Receptors, we identified the in vivo phosphorylation sites of NPR-A and NPR-B and found that the phosphorylation of multiple sites within their kinase homology domains is absolutely required for their activation. In this review, we give a detailed description of the phosphoPeptide mapping techniques that were used to identify and characterize these sites and discuss the potential pitfalls that are associated with them.
Shin Ichi Suga - One of the best experts on this subject based on the ideXlab platform.
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umbilical venous guanosine 3 5 cyclic phosphate cgmp concentration increases in asphyxiated newborns
Reproduction Fertility and Development, 1995Co-Authors: H Itoh, Shin Ichi Suga, Masashi Mukoyama, Takaaki Yoshimasa, Norimasa Sagawa, M Hasegawa, Takahide Mori, K NakaoAbstract:Guanosine 3',5'-cyclic phosphate (cGMP) is known to be the second messenger of Natriuretic Peptides and nitric oxide (NO). To investigate the involvement of Natriuretic Peptides in the regulation of the feto-placental circulation, specific radioimmunoassays were used to measure the concentrations of atrial Natriuretic Peptide (ANP), brain Natriuretic Peptide (BNP) and cGMP in the umbilical venous plasma of normal and asphyxiated newborns. The plasma concentrations of ANP, BNP and cGMP in asphyxiated newborns were 48.3 +/- 12.9 pm, 24.5 +/- 9.4 pm and 4.4 +/- 1.6 nM (mean +/- s.e.m., n = 10), respectively. These values were significantly higher than those in the normal newborns (17.4 +/- 1.9 pm, 4.7 +/- 1.0 pm, and 0.78 +/- 0.14 nM, respectively). Moreover, the expression of both ANP-A and ANP-B receptor, biologically active Receptors for Natriuretic Peptides, was detected in term human placenta by Northern bolt analysis. The expression of Natriuretic Peptide Receptors was further confirmed by binding assay using [125I]-labelled ANP and solubilized crude membrane preparations of placental tissue. These findings suggest that cGMP is produced in the placenta, at least partly, by the action of ANP and BNP secreted from fetal heart, in pathophysiological conditions such as fetal hypoxia.
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phenotype related alteration in expression of Natriuretic Peptide Receptors in aortic smooth muscle cells
Circulation Research, 1992Co-Authors: Shin Ichi Suga, K Nakao, Ichiro Kishimoto, Kiminori Hosoda, Masashi Mukoyama, Hiroshi Arai, Gotaro Shirakami, Yoshihiro Ogawa, Yasato Komatsu, Osamu NakagawaAbstract:To elucidate the physiological and pathophysiological roles of the Natriuretic Peptide family in vascular smooth muscle cells, in which the Natriuretic Peptide family is implicated in growth inhibition as well as vasorelaxation, we have examined the phenotype-related expression of three kinds of Natriuretic Peptide Receptors in rat aortic smooth muscle cells. The expression of Natriuretic Peptide Receptors at the mRNA level was studied by Northern blot hybridization, and the expression at the protein level was determined by the cGMP production method and receptor binding assay. In intact aortic media, atrial Natriuretic Peptide (ANP)-A receptor mRNA and ANP-B receptor mRNA were detected, and the potency of cGMP production by ANP was at least two orders of magnitude stronger than that by C-type Natriuretic Peptide. Clearance receptor mRNA was undetectable, and only a small amount of the clearance receptor was detected by the binding assay in intact aortic media. By contrast, in cultured aortic smooth muscle cells at the first, fifth, and 17th passages, the ANP-B receptor mRNA level markedly increased; meanwhile, the expression of the ANP-A receptor mRNA became undetectable. C-type Natriuretic Peptide was one order of magnitude more potent than ANP in cGMP production in cultured aortic smooth muscle cells. The clearance receptor density and its mRNA level increased tremendously in these cultured cells. These results demonstrate that the marked phenotype-related alteration occurs in the expression of Natriuretic Peptide Receptors in rat aortic smooth muscle cells.
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characterization of Natriuretic Peptide Receptors in cultured cells
Hypertension, 1992Co-Authors: Shin Ichi Suga, K Nakao, Kiminori Hosoda, Masashi Mukoyama, Hiroshi Arai, Yoshihiro Ogawa, Hiroo ImuraAbstract:To elucidate physiological and clinical implications of the Natriuretic Peptide family, the expression of Receptors for Natriuretic Peptides has been examined in cultured cells (a rat pheochromocytoma cell line [PC12], bovine endothelial cells, rat aortic smooth muscle cells, human mesangial cells, and a porcine kidney epithelial cell line [LLC-PK1]) by Northern blot analysis and cyclic GMP production method for the ANP-A and ANP-B Receptors and by Northern blot analysis and binding assay for the clearance receptor. The ANP-A receptor was predominantly expressed in PC12 cells, bovine endothelial cells, and LLC-PK1 cells but was barely expressed in rat aortic smooth muscle cells and human mesangial cells. By contrast, the ANP-B receptor was the major subtype of the biologically active Receptors in rat aortic smooth muscle cells and human mesangial cells. Only a small amount of the ANP-B receptor was detected in PC12 cells, bovine endothelial cells, and LLC-PK1 cells. The clearance receptor was abundantly expressed in rat aortic smooth muscle cells and human mesangial cells and was also present in bovine endothelial cells, but it was undetectable in PC12 cells and LLC-PK1 cells. These results demonstrate that the expression of three Natriuretic Peptide Receptors varies from cell to cell, which is relevant to cell- or tissue-specific action of the Natriuretic Peptide family.