Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rep68 protein, encoded by adeno-associated virus type 2 (AAV), has been previously shown to bind to specific sequences within the viral genome and in human chromosome 19. The effect of AAV Rep protein on human cellular genes is of interest because AAV is being developed as a gene therapy vector. We have identified sequences related to the Rep recognition sequence in the AAV P5 promoter in or near the c-sis proto-oncogene and the genes coding for a hepatocyte glucose transporter, alpha-A-crystallin, and carcinoma marker GA733-1. The ability of Rep68 to bind to these sites was established by gel shift assays, and the effect of Rep68 on the expression of these genes was tested by semiquantitative reverse transcriptase PCR. Rep68 enhances the expression of the c-sis proto-oncogene, which codes for the B polypeptide of platelet-derived growth factor, a multifunctional growth factor that is involved in embryonic development, tissue regeneration, osteogenesis, fibrosis, atherosclerosis, and neoplasia.
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PMID:The Rep68 protein of adeno-associated virus type 2 stimulates expression of the platelet-derived growth factor B c-sis proto-oncogene. 867 7

We have isolated and characterized a new human endogenous provirus, which is closely related to the human retrovirus S71, but unlike S71 has a full-length pol gene. Two degenerate oligonucleotide primers based on highly conserved motifs within the active sites of two retroviral proteins (the protease and reverse transcriptase) were designed and used for PCR. An amplified product of 847 bp in length, which showed significant homology to protease and reverse transcriptase of several retroviruses, was used for high stringency hybridization with a human genomic library. The MuLV-related endogenous retrovirus sequence, designated HC2, was isolated and completely sequenced. HC2 is a provirus with complete gag and pol genes and a 3' LTR; the 5' LTR and env gene are missing. The gag and pol genes appear complete, since they contain sequences homologous to the matrix protein, capsid protein, and nucleocapsid protein of gag and to the protease, reverse transcriptase, tether, RNase H, and integrase of pol. Phylogenetic analysis suggests that although HC2 and S71 are MuLV-related retroviruses, their characters are quite distinct, being placed outside of a clade containing most of the previously characterized MuLV-related retroviruses such as GaLV, FeLV, BaEV, and SSV/SSAV.
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PMID:Human endogenous retrovirus HC2 is a new member of the S71 retroviral subgroup with a full-length pol gene. 894 25

A modified quantitative reverse transcriptase polymerase chain reaction (QRT-PCR) procedure was developed for measuring mRNA concentration, in rodent cells, of the N-methylpurine-DNA glycosylase (MPG), a ubiquitous DNA repair protein responsible for the removal of N-alkylpurines and ethenoadducts of adenine, guanine, and cytosine from DNA. The method, applicable for quantitation of any mRNA, is based on the standard approach of comparing the relative amounts of PCR products of the experimental mRNA and a known amount of an exogenous reference RNA which is nearly identical to the experimental RNA. However, unlike in the earlier procedures in which deletion or insertion sequences were added to the reference RNA template, which may affect the efficiency of PCR but are needed to generate different size PCR products, experimental and reference RNAs yield PCR products of the same size in the new method. However, prior digestion with EcoRI allows separation of the two products because a unique EcoRI site was created in the reference RNA vector by point mutations. The QRT-PCR procedure is particularly useful for studying expression of the MPG gene whose mRNA level is very low and difficult to quantitate by Northern blot analysis. The number of MPG mRNA molecules/cell in late log-phase cultures varied from about 6 to 30 in several rodent lines. The SSV-NRK rat cell line has 6 +/- 0. 2 molecules/cell, while mouse NIH3T3 cells have about 30 +/- 1 molecules/cell. If the mRNA level is indicative of the level of the active MPG enzyme, these results may imply a variation in the capacity of various lines to remove the cytotoxic and mutagenic adducts from DNA.
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PMID:Quantitative reverse transcriptase polymerase chain reaction for measuring the N-methylpurine-DNA glycosylase mRNA level in rodent cells. 905 81

SSV reverse transcriptase (RT) was purified to homogeneity and used in a radioimmunoassay. Following iodination, the homogeneity of the protein and its identity with RT were confirmed by several criteria: (1) its molecular weight on an SDS-polyacrylamide gel; (2) its precipitation by anti-SSV RT but not by antisera to other SSV proteins; (3) its cross-reactivity in RIA with antisera to other retroviral polymerases; (4) its competition in RIA by active homogeneous SSV RT but not by other purified SSV proteins; and (5) its competition in RIA by only those fractions from a poly(U)-Sepharose column possessing SSV RT activity. Competition of the labelled probe with disrupted retroviruses of the infectious primate group showed that, while a homologous RIA detected only type-specific enzyme determinants, it did not distinguish the various woolly-gibbon retroviral DNA polymerases. A more broadly reactive heterologous assay utilizing an antiserum to R-MuLV RT detected group- but not interspecies-specific enzyme determinants. A comparison of immunologic assays for RT showed that: (1) highly purified RT is not essential for reliable results in enzyme neutralization or enzyme binding assays; (2) the greater sensitivity of enzyme binding compared to enzyme neutralization assays is a function of the antibody, not of the antigen. Competition RIAs using extracts of virus-infected cells showed that infectious primate retrovirus RT could be measured in a crude system and that cellular DNA polymerases alpha, beta and gamma did not compete with the labelled probe.
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PMID:Radioimmunoassay for infectious primate retrovirus reverse transcriptase: characterization, comparison with conventional immunologic assays and applicability to cellular extracts. 1476 4


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