Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Retinoic acid receptors are ligand-dependent transcription factors that stimulate gene transcription from promoters containing retinoic acid or thyroid hormone response elements. We describe a high-affinity binding site from the rat oxytocin promoter that mediates negative transcriptional regulation by the retinoic acid receptor. To examine whether strong, constitutive transactivation domains would be capable of stimulating gene transcription when bound to this DNA binding site that normally mediates transcriptional repression, we fused the transactivation domain of the herpes simplex viral protein VP16 to the amino terminus of the retinoic acid receptor and tested the activity of the chimeric protein on the negative retinoic acid response element. This chimeric retinoic acid receptor acted as a strong, constitutive transactivator when bound to promoters containing palindromic thyroid hormone/retinoic acid response elements but surprisingly it still repressed gene transcription when bound to promoters containing the oxytocin-negative retinoic acid response element. These results suggest that a negative DNA binding site itself can inhibit the function of even potent constitutive transactivation domains, and provide evidence that tethering of a constitutive transactivation domain to DNA is insufficient to activate gene transcription.
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PMID:A negative retinoic acid response element in the rat oxytocin promoter restricts transcriptional stimulation by heterologous transactivation domains. 131 Oct 87

The following compounds were evaluated for their inhibitory activity against clinical strains of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in both primary rabbit kidney (PRK) and HeLa cell cultures: (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA), 9-(2-phosphonylmethoxyethyl)adenine (PMEA), (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC), (RS)-9-(3-hydroxy-2-phosphonylmethoxypropyl)-2,6-diaminopurine (HPMPDAP), 5-(5-bromothien-2-yl)-2'-deoxyuridine (BTDU), 5-(5-chlorothien-2-yl)-2'-deoxyuridine (CTDU), 9-(2-deoxy-2-hydroxymethyl-beta-D-erythro-oxetanosyl)guanine (OXT-G), pentosan polysulfate, heparin, dextran sulfate (MW 10,000), acyclovir, 9-(2-hydroxyethoxymethyl)guanine (ACV), (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU), 1-beta-D-arabinofuranosyl-(E)-5-(2-bromovinyl)-uracil (BVaraU), vidarabine (9-beta-D-arabinofuranosyladenine) (ara-A) and phosphonoformate (PFA). The most potent inhibitors of HSV-1 were (in order of decreasing activity in PRK cells) BVDU, ACV, BVaraU and OXT-G, their mean 50% inhibitory concentration (IC50) ranging from 0.02 micrograms/ml to 0.9 micrograms/ml. Then followed BTDU and CTDU (IC50 1-2 micrograms/ml), the sulfated polysaccharides (IC50 1.3-5.8 micrograms/ml), the phosphonylmethoxyalkyl derivatives (IC50 5.6-25 micrograms/ml),ara-A (IC50 11 micrograms/ml) and PFA (IC50 38.5 micrograms/ml). Except for BVDU, BVaraU, BTDU and CTDU, the compounds did not discriminate between HSV-2 and HSV-1. All the compounds studied could be considered specific anti-HSV agents. Their selectivity indexes varied from 3 (PFA) to 6400 (BVDU).
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PMID:Comparative activity of various compounds against clinical strains of herpes simplex virus. 132 85

9-(2-hydroxyethoxymethyl)guanine (acyclovir, ACV) and novel nucleosides, 9-(2-deoxy-2-hydroxymethyl-beta-D-erythro-oxetanocyl)guanine (oxetanocin-G, OXT-G) and (+)-9-[(1R, 2R, 3S)-2, 3-bis(hydroxymethyl)cyclobutyl]guanine (carbocyclic oxetanocin-G, carbocyclic OXT-G) possessed substantial antiviral activities against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). ACV inhibited only viral thymidine kinase positive (TK+) herpes viruses, although the latter two compounds inhibited the replications of the TK deficient (TK-) mutants of HSV-1 and HSV-2 as well as the TK+ parent strains in vitro. The TK- mutants of HSV-1 and HSV-2 (HSV-1 TK- and HSV-2 TK-) were as susceptible to OXT-G as the TK parent strains. However, the TK- mutants were less susceptible to carbocyclic OXT-G than the TK+ parent strains. We demonstrated synergistic inhibition of the replications of HSV-1 and HSV-2 by ACV and OXT-G in combination, additive inhibition of HSV-1 and HSV-2 by ACV and carbocyclic OXT-G in combination, synergistic inhibition of HSV-1 by OXT-G and carbocyclic OXT-G in combination, and additive inhibition of HSV-2 by these two compounds. We investigated the metabolism of ACV and OXT-G in HSV-1 TK(+)-, HSV-1 TK(-)- and mock-infected Vero cells by thin layer chromatography. ACV-triphosphate increased more in HSV-1 TK(+)-infected Vero cells than in HSV-1 TK(-)- and mock-infected Vero cells. The metabolism of OXT-G had almost the same pattern in HSV-1 TK(+)-, HSV-1 TK(-)- and mock-infected Vero cells. These results suggest that ACV is phosphorylated by virus-induced TK, and OXT-G is phosphorylated by cellular nucleoside and nucleotide kinases.
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PMID:Effects of acyclovir, oxetanocin-G, and carbocyclic oxetanocin-G in combinations on the replications of herpes simplex virus type 1 and type 2 in Vero cells. 133 51

In order to clarify the biological activities of (-)-oxetanocin G, and (-)-oxetanocin A and its carbocyclic analogue, (-)-carboxetanocin G, the inhibitory effects of triphosphate derivatives of these compounds (OXT-GTP, OXT-ATP, and C-OXT-GTP) on eukaryotic and viral DNA polymerases were examined. DNA polymerase alpha purified from calf thymus was weakly inhibited by OXT-GTP and OXT-ATP but strongly by C-OXT-GTP, the Ki value being 0.22 microM. On the other hand, rat DNA polymerase beta was not affected by these analogues. DNA polymerase gamma purified from bovine testes was very weakly inhibited by OXT-GTP and OXT-ATP, but not by C-OXT-GTP. DNA polymerase from herpes simplex virus type-II (HSV-II) was strongly inhibited by all three analogues, the Ki values ranging from 0.5 to 1.0 microM. Human immunodeficiency virus-encoded reverse transcriptase (HIV RT) was also strongly inhibited by these three analogues, the Ki value of C-OXT-GTP being slightly smaller than that of OXT-GTP or OXT-ATP. Analysis of products synthesized on singly primed M13 single-stranded DNA by DNA polymerase alpha, HSV-II DNA polymerase or HIV RT in the presence of the analogues revealed that OXT-GTP and C-OXT-GTP were incorporated into DNA and caused chain termination mainly at sites one or two nucleotides beyond the cytosine bases on the template.
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PMID:Inhibitory effects of triphosphate derivatives of oxetanocin G and related compounds on eukaryotic and viral DNA polymerases and human immunodeficiency virus reverse transcriptase. 138 92

Oxetanocin G(9-(2-deoxy-2-hydroxymethyl-beta-D-erythro-oxetanosyl)guanine, OXT-G) is a potent and selective agent against human cytomegalovirus (HCMV). In this study we synthesized the triphosphate form of OXT-G, OXT-GTP, and examined its effect on the activities of HCMV DNA polymerase, herpes simplex type 2 (HSV-2) DNA polymerase and human DNA polymerase alpha. OXT-GTP was found to inhibit all these polymerases in a competitive manner with respect to dGTP. The Km for dGTP and the Ki for OXT-GTP of HCMV DNA polymerase were 0.86 and 0.53 mu M, respectively, while the corresponding values of DNA polymerase alpha were 2.2 and 3.6 mu M, respectively. HPLC analysis using [3H]OXT-G also revealed that OXT-G was converted to its triphosphate form 7- to 8-fold more efficiently in HCMV-infected cells than in uninfected cells. The results suggest that both the preferential phosphorylation of OXT-G in HCMV-infected cells and the preferential inhibition of HCMV DNA polymerase by OXT-GTP may contribute towards the selective activity of OXT-G against HCMV replication.
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PMID:Mechanism of inhibition of human cytomegalovirus replication by oxetanocin G. 185 Oct 5

A series of new compounds, carbocyclic oxetanocins, have been synthesized and their anti-herpesvirus activity determined. Carbocyclic oxetanocin G (OXT-G) was most active against herpes simplex virus (HSV) and human cytomegalovirus (HCMV) among carbocyclic oxetanocins tested; the median effective concentrations (EC50) for HSV-1, -2, and HCMV were 0.23, 0.04 and 0.40 micrograms/ml, respectively. The EC50 value of carbocyclic OXT-G against HSV-2 was significantly lower than those of acyclovir, ganciclovir (DHPG) and OXT-G, while the value for HCMV was comparable to those of DHPG and OXT-G. Carbocyclic OXT-G showed much higher activity against TK+ HSV-2 than against a TK- mutant, suggesting that this compound is a good substrate for HSV-2-induced TK. The antiviral activity of the compound was only partially reversed even by the addition of 100-fold excess deoxyguanosine. The results suggest that the mode of action of carbocyclic OXT-G is different from that of OXT-G.
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PMID:Anti-herpesvirus activity of carbocyclic oxetanocin G in vitro. 255 11

A novel nucleoside with an oxetanosyl-N-glycoside has been recently isolated from a culture filtrate from Bacillus megaterium and named oxetanocin A (N. Shimada, S. Hasegawa, T. Harada, T. Tomisawa, A. Fujii, and T. Takita, J. Antibiot. 39:1623-1625, 1986). In this study, we evaluated the antiherpesvirus activity of oxetanocin A and its derivatives and found that 9-(2-deoxy-2-hydroxymethyl-beta-D-erythro-oxetanosyl)guanine (OXT-G) was very potent and selective in inhibiting the replication of human cytomegalovirus (HCMV) in vitro. The median effective concentration for HCMV strain AD169 was 1.0 microgram/ml, and that for herpes simplex virus type 2 strain 186 was 3.5 micrograms/ml. The selectivity index, based on the ratio of the median inhibitory concentration for cell growth of human diploid fibroblasts to the median effective concentration for HCMV plaque formation, was more than 300. The synthesis of HCMV-induced late polypeptides such as the 150,000-molecular-weight capsid and the 68,000-molecular-weight major matrix proteins was strongly suppressed when OXT-G (5 micrograms/ml) was added to the cultures at the beginning of infection. At this concentration of OXT-G, the amount of HCMV DNA detected in the drug-treated infected cells was less than 1/10 of that detected in the infected control cells. The results suggest that the mode of action of OXT-G is inhibition of viral replication by impairing the viral DNA synthesis.
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PMID:Selective inhibition of human cytomegalovirus replication by a novel nucleoside, oxetanocin G. 284 38

The inhibitory activities of acyclovir (ACV), 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (BV-araU), ganciclovir (GCV), 9-(2-deoxy-2-hydroxymethyl-beta-D-erythro-oxetanosyl)guanine (OXT-G), and (+)-9-[(1R,2R,3S)-2,3-bis(hydroxymethyl)Cyclobutyl]guanine (cOXT-G) on the replication of wild-type and thymidine kinase (TK)-negative strains of herpes simplex virus types 1 and 2 and varicella-zoster virus (VZV) and the wild-type strain of human cytomegalovirus were tested to clarity whether the phosphorylation of these compounds is catalyzed by viral TK or other enzymes. ACV and BV-araU had little effect on the replication of TK-negative virus strains. On the other hand, GCV, OXT-G, and cOXT-G inhibited the replication of TK-negative VZV at concentrations 10 times higher than those at which they inhibited wild-type VZV, indicating that a kinase other than TK phosphorylates GCV and OXT-G in VZV-infected cells. GCV phosphorylation activity was not detected in VZV-infected cell lysates; therefore, this activity was evaluated in COS 1 cells expressing viral TK and viral protein kinase (PK). The COS 1 cells expressing VZV TK were shown to be susceptible to all compounds tested. In contrast, VZV Pk-expressing COS 1 cells were susceptible to only GCV, OXT-G, and cOXT-G. These results suggest that VZV PK phosphorylates some nucleoside analogs, for example, GCV, OXT-G, and cOXT-G. This phosphorylation pathway may be important in the anti-VZV activities of some nucleoside analogs.
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PMID:Analysis of phosphorylation pathways of antiherpesvirus nucleosides by varicella-zoster virus-specific enzymes. 884 52