Oligonucleotide Preparation Approach for Assembly of DNA Synthons

2019 ◽  
Vol 24 (6) ◽  
pp. 556-568
Author(s):  
Aleksei V. Yantsevich ◽  
Veronika V. Shchur ◽  
Sergey A. Usanov

An effective oligonucleotide preparation approach for the thermodynamically balanced, inside-out (TBIO) PCR-based assembly of long synthetic DNA molecules (synthons) is described in the current work. We replaced the necessity to purify individual oligonucleotides with just one purification procedure per approximately 500 base pairs (bp) of duplex DNA. So for an enhanced green fluorescent protein (EGFP) gene of 717 bp, we synthesized 24 oligonucleotides with a length of 50 bases and performed just two solid-phase extraction (SPE) purification procedures. It was found that the capacity of ZipTip microextractors, usually used for sample desalting in proteomics, perfectly corresponds to the gene synthesis scale (40–60 pmol). The robustness of the approach was validated with a 65-mer oligonucleotide design of the same gene. The modification of the oligonucleotide concentration gradient from the original TBIO scheme substantially increased the purity of the PCR product. We proposed a mechanism for the formation of supramolecular structures, which often occur during TBIO assembly. By using the proposed workflow, any laboratory with a standard facility for molecular biology manipulation, a 16-channel oligonucleotide synthesizer, and a conventional thermocycler has the ability to prepare one gene with a length of about 700 bp per day.

2003 ◽  
Vol 77 (22) ◽  
pp. 12203-12210 ◽  
Author(s):  
Albert A. Rizvanov ◽  
Albert G. M. van Geelen ◽  
Sergey Morzunov ◽  
Elmer W. Otteson ◽  
Charlotte Bohlman ◽  
...  

ABSTRACT A cytomegalovirus (CMV) was isolated from its natural host, Peromyscus maniculatus, and was designated Peromyscus CMV (PCMV). A recombinant PCMV was constructed that contained Sin Nombre virus glycoprotein G1 (SNV-G1) fused in frame to the enhanced green fluorescent protein (EGFP) gene inserted into a site homologous to the human CMV UL33 (P33) gene. The recombinant CMV was used for expression and immunization of deer mice against SNV-G1. The results of the study indicate that P. maniculatus could be infected with as few as 10 virus particles of recombinant virus. Challenge of P. maniculatus with either recombinant or wild-type PCMV produced no overt pathology in infected animals. P. maniculatus immunized with recombinant virus developed an antibody response to SNV and EGFP. When rechallenged with recombinant virus, animals exhibited an anamnestic response against SNV. Interestingly, a preexisting immune response against PCMV did not prevent reinfection with recombinant PCMV.


Blood ◽  
2000 ◽  
Vol 96 (2) ◽  
pp. 719-726 ◽  
Author(s):  
Nicole Faust ◽  
Florencio Varas ◽  
Louise M. Kelly ◽  
Susanne Heck ◽  
Thomas Graf

Abstract Pluripotent hematopoietic stem cells have been studied extensively, but the events that occur during their differentiation remain largely uncharted. To develop a system that allows the differentiation of cultured multipotent progenitors by time-lapse fluorescence microscopy, myelomonocytic cells were labeled with green fluorescent protein (GFP) in vivo. This was achieved by knocking the enhanced GFP (EGFP) gene into the murine lysozyme M (lys) locus and using a targeting vector, which contains a neomycin resistant (neo) gene flanked by LoxP sites and “splinked” ends, to increase the frequency of homologous recombination. Analysis of the blood and bone marrow of thelys-EGFP mice revealed that most myelomonocytic cells, especially mature neutrophil granulocytes, were fluorescence-positive, while cells from other lineages were not. Removal of the neogene through breeding of the mice with the Cre-deleter strain led to an increased fluorescence intensity. Mice with an inactivation of both copies of the lys gene developed normally and were fertile.


Blood ◽  
2000 ◽  
Vol 96 (2) ◽  
pp. 719-726 ◽  
Author(s):  
Nicole Faust ◽  
Florencio Varas ◽  
Louise M. Kelly ◽  
Susanne Heck ◽  
Thomas Graf

Pluripotent hematopoietic stem cells have been studied extensively, but the events that occur during their differentiation remain largely uncharted. To develop a system that allows the differentiation of cultured multipotent progenitors by time-lapse fluorescence microscopy, myelomonocytic cells were labeled with green fluorescent protein (GFP) in vivo. This was achieved by knocking the enhanced GFP (EGFP) gene into the murine lysozyme M (lys) locus and using a targeting vector, which contains a neomycin resistant (neo) gene flanked by LoxP sites and “splinked” ends, to increase the frequency of homologous recombination. Analysis of the blood and bone marrow of thelys-EGFP mice revealed that most myelomonocytic cells, especially mature neutrophil granulocytes, were fluorescence-positive, while cells from other lineages were not. Removal of the neogene through breeding of the mice with the Cre-deleter strain led to an increased fluorescence intensity. Mice with an inactivation of both copies of the lys gene developed normally and were fertile.


2002 ◽  
Vol 13 (12) ◽  
pp. 4401-4413 ◽  
Author(s):  
Ewa Markiewicz ◽  
Thomas Dechat ◽  
Roland Foisner ◽  
Roy. A Quinlan ◽  
Christopher J. Hutchison

The phosphorylation-dependent anchorage of retinoblastoma protein Rb in the nucleus is essential for its function. We show that its pocket C domain is both necessary and sufficient for nuclear anchorage by transiently expressing green fluorescent protein (GFP) chimeras of Rb fragments in tissue culture cells and by extracting the cells with hypotonic solutions. Solid phase binding assays using glutathioneS-transferase-fusion of Rb pockets A, B, and C revealed a direct association of lamin C exclusively to pocket C. Lamina-associated polypeptide (LAP) 2α, a binding partner of lamins A/C, bound strongly to pocket C and weakly to pocket B. When LAP2α was immunoprecipitated from soluble nuclear fractions, lamins A/C and hypophosphorylated Rb were coprecipitated efficiently. Similarly, immunoprecipitation of expressed GFP-Rb fragments by using anti-GFP antibodies coprecipitated LAP2α, provided that pocket C was present in the GFP chimeras. On redistribution of endogenous lamin A/C and LAP2α into nuclear aggregates by overexpressing dominant negative lamin mutants in tissue culture cells, Rb was also sequestered into these aggregates. In primary skin fibroblasts, LAP2α is expressed in a growth-dependent manner. Anchorage of hypophosphorylated Rb in the nucleus was weakened significantly in the absence of LAP2α. Together, these data suggest that hypophosphorylated Rb is anchored in the nucleus by the interaction of pocket C with LAP2α–lamin A/C complexes.


2019 ◽  
Author(s):  
Junetha Syed ◽  
Saravanan Palani ◽  
Scott T. Clarke ◽  
Zainab Asad ◽  
Andrew R. Bottrill ◽  
...  

AbstractSite-specific incorporation of un-natural amino acids (UNAA) is a powerful approach to engineer and understand protein function [1-4]. Site-specific incorporation of UNAAs is achieved through repurposing the amber codon (UAG) as a sense codon for the UNAA, a tRNACUA that base pairs with an UAG codon in the mRNA and an orthogonal amino-acyl tRNA synthetase (aaRS) that charges the tRNACUA with the UNAA [5, 6]. Here, we report expansion of the zebrafish genetic code to incorporate the UNAAs, Azido-lysine (AzK), bicyclononyne-lysine (BCNK), and Diazirine-lysine (AbK) into green fluorescent protein (GFP) and Glutathione-S-transferase (GST). We also present proteomic evidence for UNAA incorporation into GFP. Our work sets the stage for the use of UNAA mutagenesis to investigate and engineer protein function in zebrafish.


2008 ◽  
Vol 2 (4) ◽  
pp. 347-353
Author(s):  
A. V. Sorokin ◽  
E. M. Nonyashvili ◽  
O. V. Kidgotko ◽  
L. K. Sasina ◽  
T. D. Aleinikova ◽  
...  

Nano LIFE ◽  
2014 ◽  
Vol 04 (04) ◽  
pp. 1441018 ◽  
Author(s):  
Yan Wang ◽  
Haixin Cui ◽  
Yongguang Yang ◽  
Xiang Zhao ◽  
Changjiao Sun ◽  
...  

The mechanism of gene delivery and expression is one of the most important concerns raised by the development of gene delivery methods. Limited investigation is performed on how magnetic nanoparticles combine with DNA and deliver gene into mammalian cells. In this context, polyethyleneimine (PEI) coated iron oxide magnetic nanoparticles (MNPs) were used as gene carriers for binding and condensing with plasmid DNA expressing enhanced green fluorescent protein (EGFP). The morphology and structure of MNP–DNA complexes were characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM). We evidenced that large amounts of DNA wrapped around the surface of MNPs and that the MNPs were physically entrapped by the DNA arranged both horizontally and vertically. EGFP gene was successfully expressed under mediation of an external magnetic field which is necessary to efficiently target EGFP gene to the cells. Fluorescence from EGFP was separately detected in the cell cytoplasm and cell nucleus.


2018 ◽  
Author(s):  
Connor Bamford ◽  
Elizabeth Wignall-Fleming ◽  
Richard Randall ◽  
Paul Duprex ◽  
Bert Rima

AbstractIn reverse genetic experiments we have isolated recombinant mumps viruses (rMuV) based on a recent clinical isolate that carry large numbers of mutations clustered in small parts of their genome and which are not caused by biased hyper-mutation. In two separate experiments we obtained such rMuV: one virus had 19 mutations in the V/P region of the genome; the other, which also contained an extra transcription unit encoding green fluorescent protein (EGFP), had 32 mutations in the N gene. These specific constellations of mutations have not been observed in naturally occurring MuV isolates. The vast majority of the mutations (48/51) are synonymous.On passage in Vero cells and human B-LCL cells, a B lymphocyte-like cell Line, these mutations appear stable as no reversal occurs to the original consensus sequences, though mutations in other genes occur and change in frequency during passage. Defective Interfering RNAs accumulate in passage in Vero cells but not in B-LCL cells. Interestingly, in all passaged samples the level of variation in the EGFP gene is the same as in the viral genes, though it is unlikely that this gene is under any functionality constraint. The stability in repeated high multiplicity passage indicates that the constellation of mutations is placing the virus on a fitness peak from which it cannot escape. What mechanism gave rise to these mutant viruses and their stability remain open questions of interest to a wider field than mumps reverse genetics alone.


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