Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cDNA encoding the human substance P receptor (SPR) was isolated and the primary structure of the protein was deduced by nucleotide sequence analysis. This SPR consists of 407 residues and is a member of the G-protein coupled receptor superfamily. Comparison of rat and human SPR sequences demonstrated a 94.5% identity. The receptor was expressed in a COS-7 cell line and displayed a Kd for Tyr-1-SP binding of 0.24 nM. Ligand displacement by naturally occurring tachykinin peptides was SP much greater than neurokinin A greater than neurokinin B. SP stimulation of transfected cells resulted in a rapid and transient inositol 1,4,5-trisphosphate response. RNA blot hybridization and solution hybridization demonstrated that SPR mRNA was about 4.5 Kb in size, and was expressed in IM-9 lymphoblast and U373-MG astrocytoma cells, as well as in spinal cord and lung but not in liver.
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PMID:Molecular cloning, structural characterization and functional expression of the human substance P receptor. 171 67

Substance P G-protein coupled receptor and the antigen recognition site of a monoclonal antibody raised against substance P share a stretch of five contiguous identical amino acids. This observation prompted us to build an atomic model of both the receptor and the antibody and to analyse their common features. In particular, we report here that a pocket of similar size and composition is present in both proteins, strongly suggesting a similarity in the mode of binding of both macromolecules to substance P. From the analysis of our models, the available data on the mode of binding of the antibody to substance P and recent data on substance P receptor mutants, we concluded that the pocket is very likely to be involved in binding of the C-terminal 'message sequence' of the tachykinin. This allowed us to suggest specific site-directed mutants of the receptor which should shed some light on the mechanism of peptide recognition by G-protein coupled receptors.
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PMID:Identifying a putative common binding site shared by substance P receptor and an anti-substance P monoclonal antibody. 756 26

In the central nervous system (CNS), dopamine is involved in the control of locomotion, cognition, affect and neuroendocrine secretion. These actions of dopamine are mediated by five different receptor subtypes, which are members of the large G-protein coupled receptor superfamily. The dopamine receptor subtypes are divided into two major subclasses: the D1-like and D2-like receptors, which typically couple to Gs and Gj mediated transduction systems. In the CNS, the various receptor subtypes display specific anatomical distributions, with D1-like receptors being mainly post-synaptic and D2-like receptors being both pre- and post-synaptic. D1 and D2 dopamine receptors, the most abundant subtypes in the CNS, appear to be expressed largely in distinct neurons. Substance P and dynorphin, which are expressed in D1 receptor-containing neurons, as well as pre-proenkephalin in D2 receptor-containing neurons, have been used as monitors of dopaminergic activity in the CNS. Expression of immediate early genes, in particular fos, has also been found to correlate with dopaminergic transmission. Dopamine released from the hypothalamus controls the synthesis and secretion of prolactin from the anterior pituitary via D2 dopamine receptors. As yet none of the dopamine receptor subtypes have been associated with the etiology of psychotic disorders, such as schizophrenia. However, the recent characterization of D3 and D4 receptors which are, interestingly, expressed in areas of the CNS mediating cognition and affect or showing increased affinity for certain neuroleptics, have renewed the interest and hope of finding effective neuroleptics devoid of side effects. Finally, the recent production of genetically-derived animals lacking several of these receptor genes should help elucidate which specific physiological paradigms the receptors mediate.
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PMID:Dopamine receptors and brain function. 902 98

In this study, we have used radioligand binding and functional techniques to investigate tachykinin receptors in the small intestine of the cane toad Bufo marinus. The radioligand [125I]Bolton-Hunter [Sar9,Met(O2)11]substance P (selective at mammalian NK-1 receptors) showed no specific binding. Specific binding of [125I]Bolton-Hunter substance P ([125I]BHSP) was saturable, of high affinity (Kd 0.3 nM) and was inhibited by SP (IC50 0.64 nM) > ranakinin approximately neurokinin A (NKA) > or = SP(5-11) > or = neuropeptide gamma > or = scyliorhinin II > scyliorhinin I > or = [Sar9]-SP > or = neurokinin B approximately physalaemin approximately carassin >> SP(7-11) approximately eledoisin > or = SP(4-11) approximately SP(6-11). Binding was also inhibited by Gpp[NH]p > or = GTPgammaS > App[NH]p, indicating a G-protein coupled receptor. The order of potency of tachykinins and analogues in contracting the isolated lower small intestine was carassin (EC50 1.4 nM) > eledoisin approximately SP > or = physalaemin > or = ranakinin > SP(6-11) > scyliorhinin II > or = neuropeptide gamma > neurokinin B approximately NKA approximately scyliorhinin I > or = SP(4-11) > or = SP(5-11) > [Sar9]SP > SP(7-11). In both studies, the selective mammalian NK-1, NK-2 and NK-3 receptor agonists [Sar9,Met(O2)11]SP, [Lys5,Me-Leu9,Nle10]NKA(4-10) and senktide were weak or ineffective. There was a strong positive correlation between the pD2 and pIC50 values for mammalian tachykinins and analogues (r = 0.907), but not for the non-mammalian tachykinins, which were all full agonists but variable binding competitors. [Sar9,Met(O2)11]-SP(pD2 5.7) was approximately 25-fold less potent as an agonist than [Sar9]SP, which was itself 25-fold weaker than SP. Responses to SP were significantly reduced (n = 8, P<0.001) by the antagonist [D-Arg1,D-Trp7,9,Leu11]-SP (spantide; 1 microM). Highly selective NK-1 receptor antagonists including CP 99994 and GR 82334 (both 1 microM) were ineffective in both functional and binding studies. Tetrodotoxin (1 microM) did not inhibit contractile responses to SP, NKA and senktide. In summary, this study has shown the presence of one or more tachykinin receptor in the toad intestine. The binding site recognised by [125I]BHSP prefers SP and ranakinin. This toad "NK-1-like receptor" differs from the mammalian NK-1 receptor in having a low affinity for all mammalian NK-1 selective ligands, including antagonists. For some non-mammalian peptides, their high potency as contractile agonists relative to their poor binding affinity suggests the existence of other tachykinin receptors in the toad small intestine.
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PMID:Tachykinin receptors in the small intestine of the cane toad (Bufo marinus): a radioligand binding and functional study. 968 47

The structurally related neuropeptides, substance P (SP), neurokinin A (NKA), and neurokinin B (NKB), which belong to a family of molecules termed tachykinins and are widely distributed in the central and peripheral nervous systems, influence the function of many tissues. SP and NKA have links to the following chronic diseases: asthma, inflammatory bowel disorders, rheumatoid arthritis, pain and psychiatric disorders. These peptides exert their effects through three G-protein coupled receptor subtypes, namely, the NK1, NK2, and NK3 receptors. Non-peptide antagonists of these receptors may provide opportunities for disease treatments. In this review, the very recent advances in nonpeptide neurokinin receptor antagonists will be described with an emphasis on structure-activity relationships which have been developed.
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PMID:Recent advances in neurokinin receptor antagonists. 1010 Dec 18

Substance P is a member of the tachykinin family of neuropeptides that plays an important role in pain transmission, neurogenic inflammatory diseases and the adaptive response to stress. Substance P exerts its biological activities via binding to a G-protein coupled receptor of the neurokinin (NK) receptor family. Here, we show by Western blot experiments that substance P induced a transient synthesis of the zinc finger transcriptional regulator Egr-1 in human glioma cells. Substance P-induced stimulation of Egr-1 biosynthesis was completely inhibited by the mitogen-activated protein kinase kinase inhibitor PD98059 and by AG1487, an epidermal growth factor (EGF) receptor-specific tyrosine kinase inhibitor. These results indicate that transactivation of the EGF receptor as well as stimulation of the mitogen activated/extracellular signal-regulated protein kinase (ERK) are essential for substance P/NK-1 receptor-induced activation of Egr-1 biosynthesis. Moreover, we show that the signaling cascade initiated by substance P or EGF are indistinguishable, including the activation of the EGF receptor, the activation of ERK, and the final stimulation of Egr-1 biosynthesis. The synthesis of Egr-1 in glioma cells as a result of substance P stimulation suggests that substance P exerts long-term effects in glioma cells via Egr-1-mediated gene transcription.
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PMID:Substance P induced biosynthesis of the zinc finger transcription factor Egr-1 in human glioma cells requires activation of the epidermal growth factor receptor and of extracellular signal-regulated protein kinase. 1238 23

The technical difficulties associated with the structure determination of membrane proteins have limited the structural information available for the ligand binding to G-protein coupled receptors (GPCRs). Here, we describe a reductionist approach to GPCR structure determination in which the extracellular domains of the receptor are examined by high-resolution NMR in the presence of a membrane mimetic. The resulting structural features are then incorporated into a molecular model of the receptor, utilizing the x-ray structure of rhodopsin to generate the topological orientation of the transmembrane helices. The results of our study of the neurokinin-1 receptor (NK-1R) and its interactions with substance P (SP) are detailed here. The structure of the N-terminus, NK-1R(1-39), and of the third extracellular loop, NK-1R(264-290), in the presence of dodecylphosphocholine micelles is described. Our findings provide a structural basis for the interpretation of the results from other methods including mutagenesis, fluorescence, and photoaffinity labeling experiments, resulting in an experimentally based, high-resolution model of SP binding to NK-1R.
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PMID:Extracellular domains of the neurokinin-1 receptor: structural characterization and interactions with substance P. 1253 62

(1) The involvement of Rho-kinase (ROCK) in the contractile mechanisms mediating smooth muscle contraction of the rat urinary bladder was investigated using expression studies and the ROCK inhibitor Y-27632. (2) Both isoforms of ROCK (ROCK I and ROCK II) were detected in high levels in rat urinary bladder. (3) Y-27632 (10 micro M) significantly attenuated contractions of rat urinary bladder strips evoked by the G-protein coupled receptor agonists carbachol (58.1+/-10.5% at 0.3 micro M) and neurokinin A (68.6+/-12.7% at 1 micro M) without affecting contractions to potassium chloride (10-100 mM). In addition, basal tone was reduced by 47.8+/-2.0% by 10 micro M Y-27632 in the absence of stimulation. (4) Contractions of urinary bladder strips evoked by the P2X receptor agonist alpha,beta-methylene ATP (alpha,beta-mATP; 10 micro M) were also attenuated by Y-27632 (30.0+/-7.2% at 10 micro M). (5) Y-27632 (10 micro M) significantly attenuated contractions evoked by electrical field stimulation (2-16 Hz). The effect of Y-27632 on the tonic portion of the neurogenic response (4-16 Hz) was not significantly different from the effect of atropine (1 micro M) alone. (6) While the mechanism underlying the ability of Y-27632 to inhibit alpha,beta-mATP-evoked contractions remains undetermined, the results of the present study clearly demonstrate a role for ROCK in the regulation of rat urinary bladder smooth muscle contraction and tone.
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PMID:Expression and functional role of Rho-kinase in rat urinary bladder smooth muscle. 1264 76

The study of tachykinin NK1 (substance P) receptor antagonists has emerged as a field of great promise due to accumulating evidence that NK1 antagonists offer possible new treatment options in therapeutic areas ranging from pain, emesis, and pulmonary disorders to depression and anxiety. It is hoped that the unique mechanism of action of these agents, which involves modulation of effects mediated by the interaction of the neuropeptide substance P with it's G-protein coupled receptor, will provide improvements over existing therapies. For this reason many pharmaceutical companies are engaged in intense research programs with the goal of bringing safe and effective new drugs to the market. To date a wealth of diverse NK1 antagonists have been discovered, several of which have been evaluated in clinical trials. Despite rich structural diversity in this area of medicinal chemistry a number of structural features are commonly shared amongst otherwise unrelated antagonists. This theme and others are covered with the aim of conveying recent successful approaches to the discovery of potent and selective nonpeptide NK1 antagonists. This review focuses mainly on reports appearing in the year 2001 and the first half of 2002.
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PMID:Medicinal chemistry of selective neurokinin-1 antagonists. 1287 Nov 73

1. Nociceptin/orphanin FQ (N/OFQ) is the endogenous peptide ligand for a specific G-protein coupled receptor, the N/OFQ peptide receptor (NOP). The N/OFQ-NOP receptor system has been reported to play an important role in pain, anxiety and appetite regulation. In airways, N/OFQ was found to inhibit the release of tachykinins and the bronchoconstriction and cough provoked by capsaicin. 2. Here we evaluated the effects of NOP receptor activation in bronchoconstriction and airway microvascular leakage induced by intraesophageal (i.oe.) hydrochloric acid (HCl) instillation in rabbits. We also tested the effects of NOP receptor activation in SP-induced plasma extravasation and bronchoconstriction. 3. In anesthetized New Zealand rabbits bronchopulmonary function (total lung resistance (R(L)) and dynamic compliance (C(dyn))) and airway microvascular leakage (extravasation of Evans blue dye) were evaluated. 4. Infusion of i.oe. HCl (1 N) led to a significant increase in bronchoconstriction and plasma extravasation in the main bronchi and trachea of rabbits pretreated with propranolol, atropine and phosphoramidon. 5. Bronchoconstriction and airway microvascular leakage were inhibited by N/OFQ (3-30 microg kg(-1) i.v.) in a dose-dependent manner. The NOP receptor agonist [Arg14,Lys15]N/OFQ mimicked the inhibitory effect of N/OFQ, being 10-fold more potent, UFP-101, a peptide selective NOP receptor antagonist, blocked the inhibitory effects of both agonists. 6. Under the same experimental conditions, N/OFQ and [Arg14,Lys15]N/OFQ did not counteract the bronchoconstriction and airway microvascular leakage induced by substance P. 7. These results suggest that bronchoconstriction and airway plasma extravasation induced by i.oe. HCl instillation are inhibited by activation of prejunctional NOP receptors.
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PMID:Activation of the nociceptin/orphanin FQ receptor reduces bronchoconstriction and microvascular leakage in a rabbit model of gastroesophageal reflux. 1568 13


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