Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Receptor recycling plays a critical role in the regulation of cellular responsiveness to environmental stimuli. Agonist-promoted phosphorylation of G protein-coupled receptors has been related to their desensitization, internalization, and sequestration. Dephosphorylation of internalized G protein-coupled receptors by cytoplasmic phosphatases has been shown to be pH-dependent, and it has been postulated to be necessary for receptors to recycle to the cell surface. The internalized V2 vasopressin receptor (V2R) expressed in HEK 293 cells is an exception to this hypothesis because it does not recycle to the plasma membrane for hours after removal of the ligand. Because this receptor is phosphorylated only by G protein-coupled receptor kinases (GRKs), the relationship between recycling and GRK-mediated phosphorylation was examined. A nonphosphorylated V2R, truncated upstream of the GRK phosphorylation sites, rapidly returned to the cell surface after removal of vasopressin. Less-drastic truncations of V2R revealed the presence of multiple phosphorylation sites and suggested a key role for a serine cluster present at the C terminus. Replacement of any one of Ser-362, Ser-363, or Ser-364 with Ala allowed quantitative recycling of full-length V2R without affecting the extent of internalization. Examination of the stability of phosphate groups incorporated into the recycling S363A mutant V2Rs revealed that the recycling receptor was dephosphorylated after hormone withdrawal, whereas the wild-type V2R was not, providing molecular evidence for the hypothesis that GRK sites must be dephosphorylated prior to receptor recycling. These experiments uncovered a role for GRK phosphorylation in intracellular sorting and revealed a GRK-dependent anchoring domain that blocks V2R recycling.
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PMID:A serine cluster prevents recycling of the V2 vasopressin receptor. 948 66

Familial neurohypophyseal diabetes insipidus (FNDI) is an autosomal dominant disease caused by deficiency in the antidiuretic hormone arginine vasopressin (AVP) encoded by the AVP-neurophysin II (AVP-NPII) gene on chromosome 20p13. In this study, we analyzed two families with FNDI using direct automated fluorescent, solid phase, single-stranded DNA sequencing of PCR-amplified AVP-NPII DNA. In one of the families, affected individuals presented a novel nonsense mutation in exon 3 of the gene, consisting in a G to T transition at nucleotide 2101, which produces a stop signal in codon 82 (Glu) of NPII. The premature termination eliminates part of the C-terminal domain of NPII, including a cysteine residue in position 85, which could be involved in the correct folding of the prohormone. In the second family, a G279A substitution at position -1 of the signal peptide was observed in all affected individuals. This missense mutation, which replaces Ala with Thr, is frequent among FNDI patients and is thought to reduce the efficiency of cleavage by signal peptidases.
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PMID:Identification of a novel nonsense mutation and a missense substitution in the vasopressin-neurophysin II gene in two Spanish kindreds with familial neurohypophyseal diabetes insipidus. 958 Jan 32

The mechanism of arginine vasopressin (AVP) action in Leydig cells was investigated, and compared to the effects of phorbol-13-myristate-12-acetate (PMA) and interleukin-1 beta (IL-1 beta). Previous reports suggested that AVP inhibits Leydig cell testosterone production at the level of 17 alpha-hydroxylase/C17-lyase activity. The present study confirms and extends these observations, and contrasts the effects of AVP to IL-1. In all experiments, macrophage-depleted Leydig cells were isolated from mice and maintained in primary culture for 5 d prior to initiation of treatments. Leydig cells were treated with 8-Br-cAMP plus increasing concentrations of AVP or IL-1 beta. AVP caused a significant and dose-dependent inhibition of cAMP-stimulated testosterone production and P450c17 mRNA expression. IL-1 beta completely inhibited cAMP-stimulated testosterone production and P450c17 mRNA expression. PMA is a known activator of protein kinase C (PKC) and has been reported to inhibit Leydig cell steroidogenesis. Leydig cells express type V1 vasopressin receptors, which are coupled to PKC activation. The mechanism of IL-1 action in Leydig cells is not understood, but activation of the PKC pathway has been suggested for IL-1 action in other systems. Therefore, the effects of PMA on cAMP-stimulated steroidogenesis were compared to AVP and IL-1. Similar to the effects of AVP, PMA inhibited cAMP-stimulated testosterone production and P450c17 mRNA expression. To assess the possible involvement of PKC in AVP and IL-1 action in Leydig cells, the PKC inhibitor Calphostin C was tested. cAMP-stimulated testosterone production and P450c17 mRNA expression were significantly inhibited by 10 nM AVP (p < 0.05), and this inhibition was reversed by treatment with Calphostin C. Analogous experiments were performed to assess the role of PKC in IL-1 action. In contrast to the results for AVP, Calphostin C did not reverse the inhibitory effects of IL-1 on cAMP-stimulated P450c17 mRNA expression. To assess further PKC activation, myristoylated alanine-rich C kinase substrate (MARCKS) phosphorylation was analyzed. Only AVP and PMA, but not IL-1 beta, caused an increase in MARCKS phosphorylation. These results confirm that AVP and PMA activate PKC and indicate that IL-1 likely does not activate PKC in Leydig cells. The implications of AVP-mediated inhibition of steroidogenesis and potential role of MARCKS phosphorylation are discussed.
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PMID:Arginine vasopressin inhibition of cytochrome P450c17 and testosterone production in mouse Leydig cells. 966 41

We report an 18-year-old male with a history of polyuria, polydipsia, and thirst since childhood. In a hypertonic saline infusion test, the patient's plasma vasopressin rose only to 0.28 pg/ml. In a water deprivation test, his urinary osmolality rose only to 189 mosmol/kg and then rose to 538 mosmol/kg by vasopressin administration. A T1-weighted magnetic resonance imaging (MRI) scan revealed a loss of the posterior pituitary bright spot. Sequencing of the vasopressin gene showed a heterozygous point mutation that replaced Ala at the carboxyterminus of the signal peptide with Thr. His father also had similar history, and we therefore diagnosed his illness as familial central diabetes insipidus.
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PMID:Central diabetes insipidus associated with a missense mutation in the arginine vasopressin gene that replaces Ala at the carboxyterminus of the signal peptide with Thr. 980 74

The microdialysis technique was used to study the effects of adrenergic agonists on the release of amino acids from rat skeletal muscle. The release was monitored indirectly by measurements of interstitial concentrations. To distinguish metabolic from vasoactive effects, the adrenaline and isoprenaline results were compared with those of vasopressin, alpha-agonists and adenosine. As determined by the microdialysis ethanol technique, adrenaline, alpha-agonists and vasopressin induced vasoconstriction, whereas isoprenaline and adenosine induced vasodilatation. The lactate-to-pyruvate ratio increased fourfold with adrenaline (P < 0.001) and by 54% with isoprenaline (P < 0.05), whereas no change was observed with alpha-agonists and adenosine. Vasopressin induced a fivefold increase in the lactate-to-pyruvate ratio (P < 0.001), but with an unchanged pyruvate concentration, indicating that the effect may have been secondary to ischaemia. Adrenaline induced a twofold and vasopressin a 34% increase in the concentration of alanine (P < 0.001), whereas isoprenaline, adenosine and alpha-agonists had no significant effect. Adrenaline-perfusion induced an initial anabolic effect as evidenced by a reduced concentration of tyrosine. A significant decrease in the glutamate-to-glutamine ratio was observed with adrenaline and isoprenaline (22 and 27%, P < 0.01) whereas alpha-agonists, vasopressin and adenosine were without effect. In conclusion, the present study showed that adrenaline, via a beta-adrenergically mediated activation of glycogenolysis, possibly further stimulated by ischaemia, induced an increased release of alanine from skeletal muscle. The study indicates a beta-adrenergic stimulation on the glutamine synthetase step and a short lasting anabolic effect of adrenaline. Differences in the magnitude of the effects of adrenaline and isoprenaline could be related to their different vasoactive properties.
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PMID:Influence of adrenergic agonists on the release of amino acids from rat skeletal muscle studied by microdialysis. 978 78

The substitution, in the human V2 vasopressin receptor, of the aspartate at position 136 by alanine leads to agonist-independent activation of this mutant V2 receptor. Pharmacological studies of the D136A V2 receptor helped us in characterizing different V2 receptor antagonists. SR-121463A and OPC-31260, two non-peptide antagonists, behaved as inverse agonists, while two cyclic peptides d(CH2)5[D-Tyr(Et)2,-Val4,Tyr-NH(2)9]AVP and d(CH2)5[D-Ile2,Ile4,Tyr-NH(2)9]AVP known to be V2 antagonists, demonstrated clear partial agonist properties. The finding of a constitutively activated human V2 receptor represents a useful tool in characterizing V2 receptor antagonist ligands.
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PMID:The D136A mutation of the V2 vasopressin receptor induces a constitutive activity which permits discrimination between antagonists with partial agonist and inverse agonist activities. 989 93

The human V2 vasopressin receptor contains one consensus site for N-linked glycosylation at asparagine 22 in the predicted extracellular amino terminal segment of the protein. This segment also contains clusters of serines and threonines that are potential sites for O-glycosylation. Mutagenesis of asparagine 22 to glutamine abolished N-linked glycosylation of the V2 receptor (N22Q-V2R), without altering its function or level of expression. The N22Q-V2R expressed in transfected cells migrated in denaturing acrylamide gels as two protein bands with a difference of 7000 Da. Protein labeling experiments demonstrated that the faster band could be chase to the slower one suggesting the presence of O-linked sugars. Sialidase treatment of membranes from cells expressing the N22Q-V2R or of immunoprecipitated metabolically labeled V2R accelerated the migration of the protein in acrylamide gels demonstrating the existence of O-glycosylation, the first time this type of glycosylation has been found in a G protein coupled receptor. Synthesis of metabolically labeled receptor in the presence of 1 mM phenyl-N-acetyl-alpha-D-galactosaminide, a competitive inhibitor of N-acetyl-alpha-D-galactose and N-acetylneuraminic acid transferases, also produced a receptor that migrated faster in denaturing gels. Serines and threonines present in the amino terminus were analyzed by alanine scanning mutagenesis to identify the acceptor sites. O-glycosylation was found at most serines and threonines present in the amino terminus. Because the disappearance of a site opened the availability of others to the transferases, the exact identification of the acceptor sites was not feasible. The wild type V2R expressed in HEK 293, COS, or MDCK cells underwent N- and O-linked glycosylation. The mutant V2R bearing all serine/threonine substitutions by alanine at the amino terminus yielded a receptor functionally indistinguishable from the wild type protein, whose mobility in polyacrylamide gels was no longer affected by sialidase treatment.
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PMID:O-Glycosylation of the V2 vasopressin receptor. 1036 43

The effects of opioid peptides on the osmotic release of neurohypophyseal hormones, arginine vasotocin (AVT) and mesotocin (MT), were determined in 2-day-old chicks. Experiment 1 examined the effect of a variety of doses of naloxone, an opioid antagonist, on chicks administered isotonic or hypertonic solution. Plasma osmolality in chicks administered hypertonic solution was significantly higher than that in groups administered isotonic solution. None of the doses of naloxone affected plasma osmolality in response to isotonic and hypertonic solution. Plasma levels of AVT increased in hypertonic solution and this response was further enhanced by naloxone injection as the doses increased. The hypertonic solution alone did not affect plasma levels of MT, but additional treatment with naloxone slightly increased plasma levels of MT. Experiment 2 examined the effect of DAMGO ([d-Ala(2), N-Me-Phe(4),Gly-ol]-enkepha lin), a specific mu receptor agonist. Relatively high plasma osmolality caused by hypertonic solution was not affected by additional treatment with DAMGO. Plasma levels of AVT in response to hypertonic solution and to additional treatment with naloxone were reduced by higher doses of DAMGO. Experiment 3 examined the effect of naloxone on chicks administered different concentrations of NaCl. Administration of hypertonic solution resulted in an increase in plasma osmolality and plasma levels of AVT. Naloxone administration enhanced the increase in plasma AVT levels in response to hypertonic solution. Experiment 4 examined the effect of naloxone on different kinds of hypertonic solution, 0.15 M NaCl, 1.5 M NaCl, 2.55 M urea, and 1.95 M sucrose. The increases in plasma osmolality resulting from the administration of the urea and sucrose solutions were the same as those in the chicks injected with 1.5 M NaCl. In sucrose-treated chicks, plasma levels of AVT increased in chicks administered naloxone but not in chicks injected with normal saline. In contrast, no significant changes in plasma levels of AVT were observed in urea treatment with or without naloxone. In Experiments 3 and 4, plasma levels of MT after administration of hypertonic solutions did not change. However, naloxone administration enhanced plasma levels of MT in osmotically stimulated chicks. The results of the present study suggest that opioid peptides attenuate the increase in plasma AVT and MT in hypertonic states.
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PMID:Effects of naloxone on neurohypophyseal peptide release by hypertonic stimulation in chicks. 1041 36

The autosomal dominant form of familial neurohypophyseal diabetes insipidus (adFNDI) is a rare disease characterized by postnatal onset of polyuria and a deficient neurosecretion of the antidiuretic hormone, arginine vasopressin (AVP). Since 1991, adFNDI has been linked to 31 different mutations of the gene that codes for the vasopressin-neurophysin II (AVP-NPII) precursor. The aims of the present study were to relate the clinical phenotype to the specific genotype and to the molecular genetic effects of the most frequently reported adFNDI mutation located at the cleavage site of the signal peptide of AVP-NPII [Ala(-1)Thr]. Genetic analysis and clinical studies of AVP secretion, urinary AVP, and urine output were performed in 16 affected and 16 unaffected family members and 11 spouses of a Danish adFNDI kindred carrying the Ala(-1)Thr mutation. Mutant complementary DNA carrying the same mutation was expressed in a neurogenic cell line (Neuro2A), and the cellular effects were studied by Western blotting, immunocytochemistry, and AVP measurements. The clinical studies showed a severe progressive deficiency of plasma and urinary AVP that manifested during childhood. The expression studies demonstrated that the Ala(- 1)Thr mutant cells produced 8-fold less AVP than wild-type cells and accumulated excessive amounts of 23-kDa NPII protein corresponding to uncleaved prepro-AVP-NPII. Furthermore, a substantial portion of the intracellular AVP-NPII precursor appeared to be colocalized with an endoplasmic reticulum antigen (Grp78). These results provide independent confirmation that this Ala(-1)Thr mutation produces adFNDI by directing the production of a mutant preprohormone that accumulates in the endoplasmic reticulum, because it cannot be cleaved from the signal peptide and transported to neurosecretory vesicles for further processing and secretion.
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PMID:Clinical and molecular evidence of abnormal processing and trafficking of the vasopressin preprohormone in a large kindred with familial neurohypophyseal diabetes insipidus due to a signal peptide mutation. 1044 1

The structural requirements for internalization and signalling of the vasopressin V1a receptor were investigated in stably transfected HEK-293 cells. Removal of the 51 C-terminal amino acids did not affect vasopressin binding, calcium signalling, heterologous desensitization or internalization of the receptor. Deletion of 14 additional amino acids reduced vasopressin-dependent calcium increase and impaired receptor internalization. Substitution of cysteines 371-372 did not affect intracellular signalling, but decreased endocytosis by 26%. Substitution of the 361-362 leucine by alanine residues reduced by 56% V1a receptor sequestration without affecting calcium signalling. These results indicate that di-cysteine and mostly di-leucine motifs present in the C-terminal region of the V1a receptor are involved in its internalization.
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PMID:Role of the carboxyl-terminal region, di-leucine motif and cysteine residues in signalling and internalization of vasopressin V1a receptor. 1054 54


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