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:2.7.1.21 (thymidine kinase)
7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Analysis of the DNA sequence arrangement and polypeptides specified by 28 HSV-1 x HSV-2 recombinants show the following: (i) Recombinants with heterogeneous L and S components or with heterogenous inverted repeats are viable. (ii) HSV-1 and HSV-2 genes appear to be functionally equivalent and with few exceptions co-linearly arranged. Co-linear DNA maps have been established. (iii) At most two arrangements of HSV DNA are capable of replication. This is consistant with current studies suggesting that sequence arrangements are the consequence of obligatory post-synthesis repair. (iv) alpha Polypeptides map at the termini of the L and S components of HSV DNA. Although alpha ICP 27 maps entirely within the reiterated region of the L component, the template for alpha ICP 4 may lie only in part within the reiterated sequences of the S component. Of note is the finding that cells infected with a recombinant that contains both HSV-1 and HSV-2 DNA sequences in the S component, produced alpha ICP 4 of both HSV-1 and HSV-2. (v) Templates specifying beta and gamma polypeptides may in the L component and appear to be randomly distributed. (vi) The genes specifying thymidine kinase, resistance to phosphonoacetic acid and syncytial plaque morphology mapped in the L component. In addition, we have taken advantage of the rapid inhibition of host protein synthesis to map the gene(s) specifying this inhibition in the L component.
...
PMID:The use of intertypic recombinants for analysis of gene organization in herpes simplex virus. 22 47

Nontoxic concentrations of Cyclosporin A (CyA) dose-dependently inhibited herpes simplex virus (HSV) production in resting monkey kidney cells. The block was at the step of virus DNA synthesis as assessed by [3H]thymidine incorporation and by dot blot hybridization of infected cell DNA using a cloned 32P-labelled HSV DNA fragment (BamHI X) as probe. This was further supported by analysis of HSV protein synthesis in the presence of CyA as assessed by sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blot. A relative accumulation of HSV alpha- (e.g., ICP 4) and beta 1-proteins (e.g., ICP 6 and 8) was found, whereas HSV gamma 1-proteins were slightly decreased and gamma 2-proteins were markedly decreased by CyA. The production of thymidine kinase and DNA polymerase was decreased when CyA was added to HSV infected cells. The sensitivity to CyA was not escaped by thymidine kinase nor DNA polymerase deficient mutants. Passage of HSV in presence of CyA did not result in induction of drug resistance.
...
PMID:Inhibition of herpes simplex virus production in vitro by cyclosporin A. 130 45

Mouse macrophages grown from spleen cells were found to be very sensitive to the interferon (IFN) activity against herpes simplex virus type 1 (HSV-1). Therefore we have used these cells to investigate the level at which IFN blocks the replication of HSV-1. IFN treatment resulted in a strong inhibition of the induction of HSV DNA polymerase and other beta proteins. RNA hybridization experiments revealed that the amount of mRNA for the beta protein thymidine kinase was strongly reduced in IFN treated HSV-1 infected cells. Analysis of the effect of IFN on expression of the alpha genes indicated a strong inhibition of alpha protein synthesis. In contrast the synthesis of mRNA of the alpha protein ICP 4 was only moderately inhibited. The results indicate that IFN primarily acts on the translation of HSV alpha proteins.
...
PMID:Synthesis of herpes simplex virus proteins and nucleic acids in interferon-treated macrophages. 242 81

Adult mice were inoculated intracerebrally with herpes simplex virus type 2 (HSV-2), and perfused at days 5, 8, 81, 108, and 130 after infection. Trigeminal ganglia and roots were dissected out and embedded in paraffin. Four 35S-labelled DNA probes that contained immediate-early (ICP-0, ICP-4), delayed-early (thymidine kinase; TK), or late (morphological transforming region; MTR) genes were prepared. In situ hybridization methods or an immunoperoxidase antigen method using HSV-2 antibody were applied to serial sections. During acute infection, use of each of the 4 probes (ICP-0, ICP-4, TK, MTR) gave hybridization signals in a distribution similar to that of antigen. During latent infection, only the ICP-0 probe gave hybridization signals overlying neurons, while in adjacent sections, the other probes (ICP-4, TK, MTR) did not show signals. No antigen was detected during latency. Hybridization signals were also demonstrated in nuclei of neurons during latency using a non-radioactive ICP-0 probe labelled with a steroid hapten. These results suggest that the transcription of the HSV-2 genome is restricted during latency, with transcript localization to nuclei of neurons as has been described in latent HSV-1 infection. Evidence for latent ganglionic infection by in situ hybridization in this model is consistent with that obtained by ganglionic explanation and by reactivations induced by immunosuppression.
...
PMID:Herpes simplex virus type 2 transcripts in trigeminal ganglia during acute and latent infection in mice. 259 85

Using cells expressing herpes simplex virus (HSV) thymidine kinase, we investigated the metabolism of the acyclic antiherpes guanosine analog buciclovir, in relation to the effects of the drug on viral DNA and protein synthesis. In these cells the predominant metabolite of buciclovir was its triphosphate, as in the HSV-1 infected Vero cells investigated in parallel. Further metabolism of buciclovir led to incorporation into RNA and DNA. Buciclovir inhibited DNA synthesis, not RNA synthesis, and prevented an increase in the size of newly synthesized DNA. To study the relative effects of BCV on cellular and viral DNA synthesis, human TK-cells transformed to a TK+ phenotype with HSV-2 DNA, were infected with HSV-1. In these HSV-1 infected cells buciclovir-triphosphate caused a preferential inhibition of viral DNA synthesis. Despite incorporation of buciclovir into RNA, and the presence of buciclovir-triphosphate from the time of infection onwards, no effect was observed on the synthesis of the beta proteins ICP-6 and ICP-8. Presumably as a consequence of inhibition of viral DNA synthesis, the synthesis of a beta gamma protein (gD) and a gamma protein (gC) were inhibited, and synthesis of the beta proteins (ICP-6 and ICP-8) was not shut-off. Glycosylation of gC that was still synthesized, was not inhibited. Thus, the biological effects of buciclovir can be explained by its inhibition of DNA synthesis.
...
PMID:Incorporation into nucleic acids of the antiherpes guanosine analog buciclovir, and effects on DNA and protein synthesis. 283 18

We have analyzed the accumulation of herpes simplex virus type 1 RNA of the immediate early (IE; infected cell polypeptide types 4 and 0 [ICP-4 and ICP-0]), early (thymidine kinase), and early late (ICP-5) kinetic classes in the cytoplasm of infected cells in the presence of anisomycin, canavanine, or phosphonoacetic acid and in the course of a normal infection. IE RNAs were overproduced and were the only class of transcript detected in anisomycin-blocked cells. Phosphonoacetic acid treatment resulted in overaccumulation of early RNAs and underaccumulation of early late RNAs. Although low-stringency canavanine treatment resulted in accumulation of RNA from all kinetic classes, high-stringency conditions restricted accumulation of herpes simplex virus type 1 RNAs to the IE class. More importantly, the IE RNAs for ICP-4 and ICP-0 accumulated to a lesser extent under high-stringency canavanine conditions compared with their accumulation in anisomycin-treated cells. Therefore, the absence of newly synthesized viral proteins (anisomysin treatment) and the presence of analog proteins (stringent canavanine treatment) have different consequences with regard to the accumulation of these two IE RNAs. The kinetics of cytoplasmic accumulation for these RNAs was different for each class of RNA. The IE RNAs were detectable at 1 h postinfection and reached a maximum accumulation at ca. 3 h postinfection. The IE RNAs for both ICP-4 and ICP-0 persisted at late times of infection; however, they differed in that the RNA for ICP-4 remained at relatively low levels and the RNA for ICP-0 remained at relatively high levels as compared with their peak levels of accumulation. The 1.4-kilobase RNA for the herpes simplex virus type 1 thymidine kinase was detected by 2 h, with maximum accumulation occurring at ca. 5 h postinfection. After the peak of accumulation, the amount of thymidine kinase RNA declined rapidly from 8 to 14 h postinfection. The early late RNA for ICP-5 was detected between 2 and 3 h, after which accumulation increased to a peak between 8 and 10 h postinfection. The level of ICP-5 RNA remained at close to the peak level until 14 h postinfection. We also compared the accumulation of viral mRNAs in the cytoplasm with the rates of synthesis of their respective polypeptides. Our results suggest that translational controls may be involved in the regulation of IE genes but not early or late genes.
...
PMID:Accumulation of herpes simplex virus type 1 RNAs of different kinetic classes in the cytoplasm of infected cells. 298 33

Phenotypic and genetic properties of 12 markers in structural and regulatory functions of herpes simplex virus type 1 were characterized, and their recombination and segregation behavior was investigated and interpreted with reference to available information on their physical locations. The markers were: (i) ts markers in a structural glycoprotein (tsB5) and in alpha (immediate early; tsLB2, tsc75) or beta (early, delayed early; tsB1) functions with regulatory effects; together with (ii) plaque morphology (syn), phosphonoacetate resistance (Pr), and thymidine kinase (TK) phenotypes; and (iii) electrophoretically distinct variants of glycosylated (glycoprotein C, gpC; ICP10) and non-glycosylated [VP(13-14), VP23] structural and nonstructural [ICP(47-48)] polypeptides. Mean two-factor recombination frequencies ranged from 2% (for noncomplementing mutants tsLB2 and tsc75) to 35 to 40% (for unlinked markers) and were influenced by the relative contributions of parental viruses to the mixed infection. Even with control of this variable, standard deviations of mean measures of recombination frequency ranged from a minimum of 14% (with n greater than or equal to 10) to 65% (with n = 3) of mean values; no recombination frequencies higher than 55% were observed. Differences in mean two-factor recombination frequencies between a small number of loosely linked markers were, therefore, not reliable measures of real differences in linkage. Measurements of the segregation of unselected markers among recombinant progeny were, therefore, used as measures of linkage. These experiments (i) established a linkage group for markers in the long unique region of the genome additional to, but consistent with, existing physical data, i.e., TK-syn-tsB5-(tsB1.Pr)-[gpC.VP(13-14)]; (II) identified markers, e.g., ICP(47-48), linked to regulatory mutations (tsLB2, tsc75) in redundant DNA sequences; and (iii) used the segregation of these regulatory mutations and linked markers among unselected progeny to demonstrate the linkage groups: Pr-syn-TK-tsc75-ICP(47-48), [VP(13-14).gpC]-Pr-syn-TK, and TK-tsc75-[VP(13-14).gpC]. These results were most simply explained if bi- or intermolecular recombination occurred between circular molecules or molecules catenated "head-to-tail" and were incompatible with intermolecular recombination as the mechanism of isomerization of herpes simplex virus DNA.
...
PMID:Recombination and linkage between structural and regulatory genes of herpes simplex virus type 1: study of the functional organization of the genome. 624 8

The infected cell protein 4 (ICP-4), the major regulatory protein encoded by the a4 gene of the herpes simplex virus 1, binds two sites (alpha 4-1 proximal, alpha 4-1 distal) at the 5'-untranscribed domain and at the transcription initiation site (alpha 4-2) of the alpha 4 gene. Chimeric genes consisting of the 5'-untranscribed and transcribed noncoding domains of the alpha 4 gene fused to the coding sequences of the thymidine kinase gene were mutagenized to abolish binding of ICP-4 by substitution of bases, including the guanines whose methylation interferes with binding of the protein, and recombined into the viral genome. The cytoplasmic RNAs extracted from infected cells treated with cycloheximide, from untreated infected cells maintained for 4 or 8 hr, and from cells infected first with a virus deleted in the alpha 22 gene and 3 hr later with the test viruses were tested in RNase protection assay for amounts of the chimeric gene RNA relative to amounts of alpha 22 gene RNA. We report the following: (i) Mutation of the alpha 4-2 binding site resulted in a 5-to 6-fold higher accumulation of chimeric gene RNA at 4 hr and as much as 15-fold higher accumulation by 8 hr after infection. (ii) Mutations of alpha 4-1 sites by themselves had no effect on RNA accumulation. However, mutagenesis of all three sites significantly increased mRNA amounts above the levels seen in cells infected with alpha 4-2 site mutants. (iii) The mutations have no effect on accumulation of alpha 4 mRNA in the absence of ICP-4 synthesis and, therefore, the mutations had no effect on RNA stability or transcription rate. (iv) Accumulation of alpha 4 mRNA relative to that of alpha 22 mRNA is highest in the presence of cycloheximide and decreases with time after infection. We conclude that ICP-4 autoregulates the transcription of its own gene in infected cells and that binding of ICP-4 to three sites in its promoter is additive in its effects on this process.
...
PMID:Repression of the herpes simplex virus 1 alpha 4 gene by its gene product occurs within the context of the viral genome and is associated with all three identified cognate sites. 838 19

---