scholarly journals Genome-Scale Cloning and Expression of Individual Open Reading Frames Using Topoisomerase I-Mediated Ligation

1999 ◽  
Vol 9 (4) ◽  
pp. 383-392
Author(s):  
John A. Heyman ◽  
Jeremiah Cornthwaite ◽  
Luis Foncerrada ◽  
Jeremiah R. Gilmore ◽  
Erin Gontang ◽  
...  
Keyword(s):  
Topoisomerase I ◽  
Room Temperature ◽  
Pcr Amplification ◽  
Open Reading Frames ◽  
Cloning And Expression ◽  
Dna Topoisomerase ◽  
Specific Restriction ◽  
Genome Scale ◽  
Reading Frames

The in vitro cloning of DNA molecules traditionally uses PCR amplification or site-specific restriction endonucleases to generate linear DNA inserts with defined termini and requires DNA ligase to covalently join those inserts to vectors with the corresponding ends. We have used the properties of Vaccinia DNA topoisomerase I to develop a ligase-free technology for the covalent joining of DNA fragments to suitable plasmid vectors. This system is much more efficient than cloning methods that require ligase because the rapid DNA rejoining activity of Vaccinia topoisomerase I allows ligation in only 5 min at room temperature, whereas the enzyme’s high substrate specificity ensures a low rate of vector-alone transformants. We have used this topoisomerase I-mediated cloning technology to develop a process for accelerated cloning and expression of individual ORFs. Its suitability for genome-scale molecular cloning and expression is demonstrated in this report.

scholarly journals Engineering of Recombinant Sheep Pox Viruses Expressing Foreign Antigens

2021 ◽  
Vol 9 (5) ◽  
pp. 1005
Author(s):  
Olga Chervyakova ◽  
Elmira Tailakova ◽  
Nurlan Kozhabergenov ◽  
Sandugash Sadikaliyeva ◽  
Kulyaisan Sultankulova ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Viral Vector ◽  
Foot And Mouth Disease ◽  
Open Reading Frames ◽  
Foreign Gene ◽  
Mouth Disease Virus ◽  
Foreign Genes ◽  
Green Fluorescent ◽  
Reading Frames

Capripoxviruses with a host range limited to ruminants have the great potential to be used as vaccine vectors. The aim of this work was to evaluate attenuated sheep pox virus (SPPV) vaccine strain NISKHI as a vector expressing several genes. Open reading frames SPPV020 (ribonucleotide kinase) and SPPV066 (thymidine kinase) were selected as sites for the insertion of foreign genes. Two integration plasmids with expression cassette were designed and constructed. Recombinant SPPVs expressing an enhanced green fluorescent protein (EGFP) (rSPPV(RRΔ)EGFP and rSPPV(TKΔ)EGFP), Foot-and-mouth disease virus capsid protein (VP1), and Brucella spp. outer membrane protein 25 (OMP25) (rSPPV(RRΔ)VP1A-(TKΔ)OMP25) were generated under the transient dominant selection method. The insertion of foreign genes into the SPPV020 and SPPV066 open reading frames did not influence the replication of the recombinant viruses in the cells. Successful foreign gene expression in vitro was assessed by luminescent microscopy (EGFP) and Western blot (VP1 and OMP25). Our results have shown that foreign genes were expressed by rSPPV both in permissive (lamb testicles) and non-permissive (bovine kidney, saiga kidney, porcine kidney) cells. Mice immunized with rSPPV(RRΔ)VP1A-(TKΔ)OMP25 elicited specific antibodies to both SPPV and foreign genes VP1 and OMP25. Thus, SPPV NISKHI may be used as a potential safe immunogenic viral vector for the development of polyvalent vaccines.

scholarly journals Internalization of Foldamer-Based DNA Mimics through a Site-Specific Antibody Conjugate to Target HER2-Positive Cancer Cells

2021 ◽  
Vol 14 (7) ◽  
pp. 624
Author(s):  
Valentina Corvaglia ◽  
Imène Ait Mohamed Amar ◽  
Véronique Garambois ◽  
Stéphanie Letast ◽  
Aurélie Garcin ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Topoisomerase I ◽  
Ovarian Cancer Cells ◽  
Cellular Functions ◽  
Antibody Drug Conjugate ◽  
Her2 Positive ◽  
Dna Topoisomerase ◽  
Antibody Conjugate ◽  
A Site

Inhibition of protein–DNA interactions represents an attractive strategy to modulate essential cellular functions. We reported the synthesis of unique oligoamide-based foldamers that adopt single helical conformations and mimic the negatively charged phosphate moieties of B-DNA. These mimics alter the activity of DNA interacting enzymes used as targets for cancer treatment, such as DNA topoisomerase I, and they are cytotoxic only in the presence of a transfection agent. The aim of our study was to improve internalization and selective delivery of these highly charged molecules to cancer cells. For this purpose, we synthesized an antibody-drug conjugate (ADC) using a DNA mimic as a payload to specifically target cancer cells overexpressing HER2. We report the bioconjugation of a 16-mer DNA mimic with trastuzumab and its functional validation in breast and ovarian cancer cells expressing various levels of HER2. Binding of the ADC to HER2 increased with the expression of the receptor. The ADC was internalized into cells and was more efficient than trastuzumab at inhibiting their growth in vitro. These results provide proof of concept that it is possible to site-specifically graft high molecular weight payloads such as DNA mimics onto monoclonal antibodies to improve their selective internalization and delivery in cancer cells.

scholarly journals Genomic Sequence of Rhesus Cytomegalovirus 180.92: Insights into the Coding Potential of Rhesus Cytomegalovirus

2006 ◽  
Vol 80 (8) ◽  
pp. 4179-4182 ◽  
Author(s):  
Pierre Rivailler ◽  
Amitinder Kaur ◽  
R. Paul Johnson ◽  
Fred Wang
Keyword(s):  
Genomic Sequence ◽  
Open Reading Frames ◽  
Rhesus Cytomegalovirus ◽  
Human Cmv ◽  
Coding Capacity ◽  
Coding Potential ◽  
Reading Frames ◽  
Genetic Rearrangements

ABSTRACT A pathogenic isolate of rhesus cytomegalovirus (rhCMV 180.92) was cloned, sequenced, and annotated. Comparisons with the published rhCMV 68.1 genome revealed 8 open reading frames (ORFs) in isolate 180.92 that are absent in 68.1, 10 ORFs in 68.1 that are absent in 180.92, and 34 additional ORFs that were not previously annotated. Most of the differences appear to be due to genetic rearrangements in both isolates from a region that is frequently altered in human CMV (hCMV) during in vitro passage. These results indicate that the rhCMV ORF repertoire is larger than previously recognized. Like hCMV, understanding of the complete coding capacity of rhCMV is complicated by genomic instability and may require comparisons with additional isolates in vitro and in vivo.

Minor groove dimeric bisbenzimidazoles inhibit in vitro DNA binding to eukaryotic DNA topoisomerase I

2010 ◽  
Vol 75 (6) ◽  
pp. 695-701 ◽  
Author(s):  
O. Yu. Susova ◽  
A. A. Ivanov ◽  
S. S. Morales Ruiz ◽  
E. A. Lesovaya ◽  
A. V. Gromyko ◽  
...  
Keyword(s):  
Dna Binding ◽  
Topoisomerase I ◽  
Minor Groove ◽  
Dna Topoisomerase I ◽  
Dna Topoisomerase ◽  
Dimeric Bisbenzimidazoles ◽  
Eukaryotic Dna

Synthesis, crystal structure, DNA interaction and in vitro anticancer activity of a Cu(ii) complex of purpurin: dual poison for human DNA topoisomerase I and II

RSC Advances ◽  
2014 ◽  
Vol 4 (103) ◽  
pp. 59344-59357 ◽  
Author(s):  
Piyal Das ◽  
Chetan Kumar Jain ◽  
Sanjoy K. Dey ◽  
Rajat Saha ◽  
Abhishek Dutta Chowdhury ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Topoisomerase I ◽  
Dna Interaction ◽  
Dna Topoisomerase I ◽  
Oxygen Species ◽  
Dna Topoisomerase ◽  
Human Dna ◽  
Anti Tumor Activity ◽  
Human Dna Topoisomerase I

Although generation of reactive oxygen species (ROS) by anthracycline anticancer drugs is essential for anti-tumor activity, they make these drugs cardiotoxic.

E1−E4+ Adenoviral Gene Transfer Vectors Function as a “Pro-Life” Signal to Promote Survival of Primary Human Endothelial Cells

Blood ◽  
1999 ◽  
Vol 93 (9) ◽  
pp. 2936-2944 ◽  
Author(s):  
Ramachandran Ramalingam ◽  
Shahin Rafii ◽  
Stefan Worgall ◽  
Douglas E. Brough ◽  
Ronald G. Crystal
Keyword(s):  
Endothelial Cells ◽  
Open Reading Frames ◽  
Adenoviral Gene Transfer ◽  
Vector Genome ◽  
Transfer Vectors ◽  
Reading Frames ◽  
Human Endothelium ◽  
Pro Life

Abstract Although endothelial cells are quiescent and long-lived in vivo, when they are removed from blood vessels and cultured in vitro they die within days to weeks. In studies of the interaction of E1−E4+ replication–deficient adenovirus (Ad) vectors and human endothelium, the cells remained quiescent and were viable for prolonged periods. Evaluation of these cultures showed that E1−E4+ Ad vectors provide an “antiapoptotic” signal that, in association with an increase in the ratio of Bcl2 to Bax levels, induces the endothelial cells to enter a state of “suspended animation,” remaining viable for at least 30 days, even in the absence of serum and growth factors. Although the mechanisms initiating these events are unclear, the antiapoptoic signal requires the presence of E4 genes in the vector genome, suggesting that one or more E4 open reading frames of subgroup C Ad initiate a “pro-life” program that modifies cultured endothelial cells to survive for prolonged periods.

scholarly journals Characterization of Endogenous Retroviruses in Sheep

2003 ◽  
Vol 77 (20) ◽  
pp. 11268-11273 ◽  
Author(s):  
Nikolai Klymiuk ◽  
Mathias Müller ◽  
Gottfried Brem ◽  
Bernhard Aigner
Keyword(s):  
Endogenous Retrovirus ◽  
Ovis Aries ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
In Vivo Experiments ◽  
Pregnant Sheep ◽  
Reading Frames

ABSTRACT Endogenous retrovirus (ERV) sequences have been found in all mammals. In vitro and in vivo experiments revealed ERV activation and cross-species infection in several species. Sheep (Ovis aries) are used for various biotechnological purposes; however, they have not yet been comprehensively screened for ERV sequences. Therefore, the aim of the study was to classify the ERV sequences in the ovine genome (OERV) by analyzing the retroviral pro-pol sequences. Three OERV β families and nine OERV γ families were revealed. Novel open reading frames (ORF) in the amplified proviral fragment were found in one OERV β family and two OERV γ families. Hybrid OERV produced by putative recombination events were not detected. Quantitative analysis of the OERV sequences in the ovine genome revealed no relevant variations in the endogenous retroviral loads of different breeds. Expression analysis of different tissues from fetal and pregnant sheep detected mRNA from both gammaretrovirus families, showing ORF fragments. Thus, the release of retroviruses from sheep cells cannot be excluded.

scholarly journals DNA Topoisomerase I Inhibitory Activity of Quinochalcone C-glycosides from the Florets of Carthamus tinctorius

2017 ◽  
Vol 12 (11) ◽  
pp. 1934578X1701201
Author(s):  
Shi-Jun Yue ◽  
Wen-Xiao Wang ◽  
Cheng Qu ◽  
Lan-Ting Xin ◽  
Yu-Ping Tang ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Dna Cleavage ◽  
Topoisomerase I ◽  
Docking Study ◽  
Carthamus Tinctorius ◽  
In Vitro Cytotoxicity ◽  
Molecular Docking Study ◽  
Dna Topoisomerase ◽  
Cleavage Complex

The DNA topoisomerase (Topo) I inhibitory activity of six quinochalcone C-glycosides (QCGs) isolated from the florets of Carthamus tinctorius were evaluated in vitro. Among them, anhydrosafflor yellow B (AHSYB, 4) and carthorquinoside B (6) could inhibit DNA Topo I at concentrations as low as 100 μM. Molecular docking study revealed that both of them have the capacity to stabilize Topo I-DNA cleavage complex in silico interacting with the essential binding sites, such as Arg364, Thr718 and TGP11. Besides, both compounds 4 and 6 exhibited no antitumor activity by in vitro cytotoxicity assays.

scholarly journals Nucleosomes represent a physical barrier for cleavage activity of DNA topoisomerase I in vivo

2008 ◽  
Vol 409 (3) ◽  
pp. 651-656 ◽  
Author(s):  
Francesca Di Felice ◽  
Francesco Chiani ◽  
Giorgio Camilloni
Keyword(s):  
Topoisomerase I ◽  
Basic Question ◽  
Dna Topoisomerase I ◽  
Physical Barrier ◽  
Dna Topoisomerase ◽  
Histone Octamer ◽  
Cleavage Activity ◽  
Cellular Dna

DNA topoisomerase I together with the other cellular DNA topoisomerases releases the torsional stress from DNA caused by processes such as replication, transcription and recombination. Despite the well-defined knowledge of its mechanism of action, DNA topoisomerase I in vivo activity has been only partially characterized. In fact the basic question concerning the capability of the enzyme to cleave and rejoin DNA wrapped around a histone octamer remains still unanswered. By studying both in vivo and in vitro the cleavage activity of DNA topoisomerase I in the presence of camptothecin on a repeated trinucleotide sequence, (TTA)35, lying in chromosome XIII of Saccharomyces cerevisiae, we can conclude that nucleosomes represent a physical barrier for the enzyme activity.

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