Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human neuropeptide Y (NPY) gene was isolated from a human genomic DNA library. The transcription unit spans approximately 8 kilobase pairs and is interrupted by three intervening sequences. The first exon contains only nontranslated DNA. The site where transcription initiates was determined by primer extension analysis using a primer derived from a human cDNA, pheochromocytoma RNA and avian myeloblastosis virus reverse transcriptase. A TATA-like sequence and a CAAT-like sequence occur 25 and 70 base pairs 5' to the transcription start site, respectively. The second exon begins with the initiator Met for preproNPY and extends to the Arg (residue 63) which precedes the Tyr-amide of mature NPY. The third exon contains the coding region for 27 amino acids, and the fourth exon codes for the terminal heptapeptide and the 3' nontranslated DNA. Transcriptional control elements were investigated by fusing 581 base pairs of the 5' sequences of the NPY gene to the promoterless structural gene for chloramphenicol acetyltransferase. NPY promoter activity was assayed by transfection of these hybrid constructions into CA-77 and PC12 cells followed by the determination of chloramphenicol acetyltransferase activity in cellular extracts. DNA sequences located within 530 bases of the start of transcription are sufficient for transient expression in the two neuronally derived cell lines examined.
...
PMID:Characterization, sequence, and expression of the cloned human neuropeptide Y gene. 242 15

The pancreatic polypeptide family includes pancreatic polypeptide (PP), neuropeptide Y (NPY), and peptide YY (PYY). Members of the PP family regulate numerous physiological processes, including appetite, gastrointestinal transit, anxiety, and blood pressure. Of the multiple Y-type receptors proposed for PP family members, only the Y1 subtype has been cloned previously. We now report the cloning of an additional Y-type receptor, designated Y4, by homology screening of a human placental genomic library with transmembrane (TM) probes derived from the rat Y1 gene. The Y4 genomic clone encodes a predicted protein of 375 amino acids that is most homologous to Y1 receptors from human, rat, and mouse (42% overall; 55% in TM). 125I-PYY binding to transiently expressed Y4 receptors was saturable (pKd = 9.89) and displaceable by human PP family derivatives: PP (pKi = 10.25) approximately PP2-36 (pKi = 10.06) > PYY (pKi = 9.06) approximately [Leu31,Pro34]NPY (pKi = 8.95) > NPY (pKi = 8.68) > PP13-36 (pKi = 7.13) > PP31-36 (pKi = 6.46) > PP31-36 free acid (pKi < 5). Human PP decreased [cAMP] and increased intracellular [Ca2+] in Y4-transfected LMTK- cells. Y4 mRNA was detected by reverse transcriptase-polymerase chain reaction in human brain, coronary artery, and ileum, suggesting potential roles for Y4 receptors in central nervous system, cardiovascular, and gastrointestinal function.
...
PMID:Cloning and functional expression of a human Y4 subtype receptor for pancreatic polypeptide, neuropeptide Y, and peptide YY. 759 11

The neuropeptide Y-induced vasoconstriction of human cerebral arteries is mediated by the neuropeptide Y Y1 receptor. We conclude this on the basis of our results from: (1) in vitro studies on neuropeptide Y agonists. Neuropeptide Y and pro34NPY caused potent and long-lasting contractions of human cerebral arteries, while NPY 13-36 had no contractile effect at all on the vessels tested; (2) in vitro studies using the selective Y1 receptor antagonist BIBP3226 which in increasing concentrations (10(-9)-10(-6)M) caused a parallel shift to the right of the neuropeptide Y concentration-response curve without change of the maximum contractile response (pA2 value 8.38 +/- 0.10); and (3) with reverse transcriptase-polymerase chain reaction (RT-PCR) we detected specific mRNA for a neuropeptide Y Y1 receptor in human pial and human middle cerebral arteries using three forward primers and one reverse primer.
...
PMID:Presence of neuropeptide Y Y1 receptor mediating vasoconstriction in human cerebral arteries. 893 51

The aim of our study was to determine the neuropeptide Y (NPY) receptor subtype responsible for the NPY-induced contraction of human subcutaneous (s.c.) resistance arteries. To elucidate this, we used (a) in vitro studies of NPY agonists: NPY, peptide YY (PYY), and Pro34NPY induced equally strong and equipotent concentration-dependent contractions of human s.c. resistance arteries, whereas NPY13-36 and NPY18-36 had no contractile effects; (b) in vitro studies using the NPY Y1-receptor antagonist, BIBP3226, which in nanomolar concentrations inhibited the contractile effect of NPY, causing a rightward shift of the concentration-response curve. pEC50 for NPY alone, 8.41 +/- 0.21; NPY + BIBP3226, 10 nM, 7.79 +/- 0.21; NPY + BIBP3226, 100 nM, 7.18 +/- 0.18; NPY + BIBP3226, 1 microM, 6.32 +/- 0.05 (n = 5-8). Schild-plot analysis indicated competitive antagonism: pA2 = 8.53 +/- 0.22 and slope = 0.99 +/- 0.14; (c) with reverse transcriptase-polymerase chain reaction (RT-PCR), we detected messenger RNA (mRNA) encoding the human NPY Y1 receptor and a splice variant of the receptor in human s.c. resistance arteries. On the basis of the agonists' potency order, the antagonistic effect of BIBP3226 on the NPY-induced contraction, and the presence of mRNA encoding the NPY Y1 receptor, we conclude that the NPY-induced contraction of human s.c. resistance arteries is mediated by NPY Y1 receptors.
...
PMID:Contractile effects of neuropeptide Y in human subcutaneous resistance arteries are mediated by Y1 receptors. 896 Oct 73

To elucidate which neuropeptide Y receptor subtype is responsible for the neuropeptide Y-induced potentiation of the noradrenaline-evoked contraction in human omental arteries we used antisense oligodeoxynucleotide (Antisense), the new selective neuropeptide Y Y1 receptor antagonist, BIBP3226 {(R)-N2-(diphenylacetyl)-N-[(4-hydroxyphenyl) methyl]-D-arginine-amide} and the reverse transcriptase-polymerase chain reaction (RT-PCR). Neuropeptide Y significantly potentiated the noradrenaline-induced contraction in non-incubated vessels (pEC50 6.4 +/- 0.2 vs. 5.9 +/- 0.2) and in vessels incubated with 1 microM Sense oligodeoxynucleotide (Sense) (pEC50 6.0 +/- 0.1 vs. 5.6 +/- 0.2). In vessels incubated with 1 microM Antisense the potentiating effect of neuropeptide Y was completely abolished. BIBP3226 (1 microM) inhibited the neuropeptide Y-induced potentiation in human omental arteries (pEC50 5.8 +/- 0.3 vs. 6.4 +/- 0.2). Finally, messenger RNA for the neuropeptide Y Y1 receptor was detected using RT-PCR. On the basis of our results we conclude that the neuropeptide Y-induced potentiation of the noradrenaline-induced contraction is mediated by the neuropeptide Y Y1 receptor.
...
PMID:Neuropeptide Y potentiates noradrenaline-induced contraction through the neuropeptide Y Y1 receptor. 898 51

Somatostatin modulates important physiologic functions of the kidney, including mesangial cell contraction, glomerular prostaglandin synthesis, and phosphate, water and sodium excretion. In diabetic nephropathy, somatostatin inhibits renal hypertrophy. High affinity somatostatin receptors are expressed in the kidney. Circulating somatostatin concentrations, however, are generally well below the affinity constants of known somatostatin receptors. Thus, we hypothesized that somatostatin is produced in the kidney and released locally to act in an autocrine/paracrine manner. Using reverse transcriptase and polymerase chain reaction (RT-PCR) analysis, we found that fresh human renal cortex and cultured human mesangial cells express somatostatin mRNA. Restriction enzyme and Southern blot analysis confirmed that RT-PCR cDNA products were derived from somatostatin mRNA. Radioimmunoassay of mesangial cell culture supernatants demonstrated SS-immunoreactive peptide (87 +/- 30 pg/ml compared to 19 +/- 9 pg/ml in medium not exposed to cells; P < 0.05). In contrast, renal cells did not transcribe detectable levels of vasoactive intestinal peptide (VIP) or neuropeptide Y (NPY) mRNA, nor did they synthesize measurable peptide. Our results demonstrate that renal cells produce somatostatin and suggest that kidney-derived somatostatin may regulate renal function in an autocrine/paracrine manner. Characterization of this pathway may lead to novel methods to alter the course of diabetic nephropathy and other renal diseases.
...
PMID:Somatostatin expression in human renal cortex and mesangial cells. 909 50

We report here our effort of cloning and characterization of a novel human gene, which encodes a putative human endothelin receptor type B like protein (hET(B)R-LP), from a human hippocampus tissue cDNA library. hET(B)R-LP consists of 614 amino acids with seven putative transmembrane domains. The deduced amino acid sequence of hET(B)R-LP is 52% similar and 26.7% identical to human endothelin type B receptor. A 4.0 kb mRNA of hET(B)R-LP is abundantly expressed in the human brain. The results of in situ hybridization and reverse transcriptase in situ gene amplification reveal tissue distribution and cellular localization of signals of hET(B)R-LP mRNA in the neuronal cells, particularly concentrated in Purkinje cells of the cerebellum, and neuronal cells of the hippocampus of human brain, including pyramidal cells of Ammon's horn and granule cells of the dentate gyrus. A 4.0 kb mRNA of hET(B)R-LP is also less abundantly expressed in the liver and the placenta. Expression of recombinant protein, hET(B)R-LP/HA, in cells of COS7 and HEK293 transfected with plasmid DNA, hET(B)R-LP/HA/pcDNA1/Amp, was confirmed by Northern blot analysis and by immunofluorescence staining of cells with anti-HA antibody. Specific binding of radiolabeled ET-1 and ET-3 to membrane preparations and to intact cells expressing recombinant protein of hET(B)R-LP/HA did not show any significant difference of binding properties between cells transfected with plasmid DNA, hET(B)R-LP/HA/pcDNA1/Amp, and cells untransfected, including both COS7 cells and HEK293 cells. The results of assays of measuring Ca++ mobilization and cAMP production in HEK293 cells indicate that ET-1, ET-3, bombesin and neuropeptide Y are unable to produce any kind of significant difference of Ca++ mobilization and cAMP production between HEK293 cells expressing recombinant protein and HEK293 cells untransfected or HEK293 cells transfected with vector DNA only (pcDNA1/Amp) in functional assays performed. Therefore, its ligand and physiological significance of hET(B)R-LP remains to be discovered.
...
PMID:A novel endothelin receptor type-B-like gene enriched in the brain. 914 77

Numerous nerve fibers containing neuropeptide Y (NPY) and calcitonin gene-related peptide (CGRP) have been found in the human nasal mucosa by means of immunocytochemistry. We detected NPY Y1 and CGRP1 receptors at the same location using reverse transcriptase-polymerase chain reaction. The possibility of local release in connection with specific target receptors suggests a role for endogenous NPY and CGRP in the regulation of vascular tone, glandular secretion, and epithelial functions.
...
PMID:Expression of NPY Y1 and CGRP1 receptors in human nasal mucosa: implications in allergic rhinitis. 1052 52

The aim of this study was to examine dose-dependent effects of intranasal application of neuropeptide Y (NPY) on nasal mucosal blood flow, blood content, and intranasal nitric oxide (NO) concentration. Blood flow was measured by laser Doppler flowmetry (LDF) and blood content by rhinomanometry. Mucosal biopsies were taken for investigation of Y1 and Y2 receptor mRNA expression, using the reverse transcriptase-polymerase chain reaction (RT-PCR). Intranasal application of NPY evoked a dose-dependent reduction of nasal mucosal blood flow. Maximal vasoconstriction, seen at 12 nmol, was -37.5 +/- 6.2%, p < 0.05 (n = 9). The vasoconstrictive effect developed within 2 to 4 min and lasted > 17 min. NPY evoked a dose-dependent reduction of nasal airway resistance (NAR) on the ipsilateral side. Maximal decrease was -24.0 +/- 10.0% at 12 nmol, p < 0.05 (n = 9). There was a decrease in nasal NO production on the ipsilateral side after application of NPY 12 nmol (-7.4 +/- 1.2%, p < 0.05, n = 8). RT-PCR products corresponding to Y1 receptor but not Y2 receptor mRNA were obtained from biopsies of the nasal mucosa. In conclusion, NPY is a potent vasoconstrictor in the human nose reducing mucosal blood flow, as well as the blood content. The effect is probably mediated via Y1 receptors. NPY receptor agonists may prove beneficial in the treatment of the congested nose in allergic or vasomotor rhinitis.
...
PMID:Functional effects of neuropeptide Y receptors on blood flow and nitric oxide levels in the human nose. 1055 47

The aim of this study was to assess human intracranial tumours for their gene expression pattern of the vasoactive peptide adrenomedullin (AM), its receptor (AM-R) and leptin, which exerts multiple biological effects including proliferation and angiogenesis via the leptin receptor (OB-Rb). Gene activity of neuropeptide Y (NPY) was monitored additionally. We investigated whether there was a characteristic gene expression pattern of AM and leptin in different intracranial tumours, depending on their proliferation activity and biological behaviour. We investigated 35 non-functioning pituitary adenomas (including eight null cell, four silent plurihormonal, 23 silent gonadotroph adenomas), seven somatotropinomas, seven prolactinomas, eight meningiomas, five astrocytomas, two glioblastoma multiformes and unaffected temporal lobe (n = 8). Quantitative reverse transcriptase-polymerase chain reaction (TaqMan RT-PCR) was performed. AM mRNA was detectable in all tumour specimens. AM/GAPDH (glyceraldehyde-3-phosphate dehydrogenase) ratio was significantly higher in somatotropinomas, as was AM/CD31 ratio in prolactinomas, compared with inactive adenomas (P < 0.05). AM-R mRNA was found in all tumour subgroups in small quantities but, in general, higher in tumours than in temporal lobe tissue, respectively. AM-R/CD31 ratio was significantly higher in prolactinomas than in inactive adenomas (P < 0.05). Leptin was detectable in very low quantities in each subgroup. OB-Rb gene expression was found in all tumour subgroups, OB-Rb/GAPDH ratio was highest for meningiomas (P < 0.0001, compared with temporal lobe). NPY mRNA was detectable in temporal lobe in higher quantities than in tumours (P < 0.0001), and almost undetectable in prolactinomas and astrocytomas. Our data demonstrate that AM and AM-R, NPY, as well as leptin and OB-Rb, are expressed in various intracranial tumours in humans but their particular function has to be elucidated further. At present, there is no evidence for a cross-talk on transcriptional level between the peptidergic vasodilative system AM and the putative angiogenic and proliferation affecting factor leptin.
...
PMID:Gene expression of adrenomedullin, leptin, their receptors and neuropeptide Y in hormone-secreting and non-functioning pituitary adenomas, meningiomas and malignant intracranial tumours in humans. 1148 41


1 2 3 4 Next >>

---