In vitro uptake of tritium from uridine-5-H3 into RNA (and DNA) in normal and murine leukemia virus infected mouse embryo tissue

1970 ◽  
Vol 16 (11) ◽  
pp. 1095-1099 ◽  
Author(s):  
Richard A. Albach ◽  
Mariette J. Gerber ◽  
Eric R. Brown
Keyword(s):  
Mouse Embryo ◽  
Nuclear Dna ◽  
Leukemia Virus ◽  
Rnase A ◽  
Nuclear Label ◽  
Embryo Tissue ◽  
Pancreatic Rnase ◽  
Autoradiographic Analysis ◽  
Labeled Rna

The multiplication and release into the medium of a murine leukemic virus (GC) occurs in mouse embryo tissue cultures. Autoradiographic analysis of such infected and uninfected cultures after 24-h labeling periods with uridine-5-H3 demonstrated extensive nuclear and cytoplasmic activity. Such activity was always more extensive in infected cultures, indicating that they were more metabolically active than uninfected cultures. The cytoplasmic activity was apparently in single-stranded RNA, since it was completely removed with pancreatic RNase. A portion of the nuclear label which was RNase-resistant was in DNA, since RNase followed by DNase, or the reverse, removed all label.Autoradiographic analysis of cultures given pulse labels of uridine-5-H3 from 5 to 60 min revealed only nuclear label, always more extensive in infected cultures. This indicates that the synthesis of "rapidly labeled" RNA is enhanced by viral infection; this occurs even within 2 h after infection. Nuclear activity observed after 5- and 10-min pulses was removed by buffers containing RNase or DNase. Possibly this label was in diffusible low molecular weight species of RNA. After 30-min pulses, activity was exclusively associated with pancreatic RNase-sensitive single-stranded RNA. After 60-min labeling, tritium from uridine-5-H3 was taken up into nuclear DNA in addition to RNA.

Permissiveness to murine leukemia, virus expression during preimplantation and early postimplantation mouse development

Development ◽  
1990 ◽  
Vol 109 (3) ◽  
pp. 655-665
Author(s):  
P. Savatier ◽  
J. Morgenstern ◽  
R.S. Beddington
Keyword(s):  
Mouse Embryo ◽  
Murine Leukemia Virus ◽  
Inner Cell Mass ◽  
Leukemia Virus ◽  
Cell Mass ◽  
Lacz Gene ◽  
Mouse Development ◽  
Beta Galactosidase ◽  
Murine Leukemia

Permissiveness to Moloney Murine Leukemia Virus (MoMuLV) expression was examined during preimplantation and early postimplantation development of the mouse embryo. Blastocysts and 8th, 9th and 10th day postimplantation embryos were infected in vitro with a MoMuLV-based retroviral vector expressing the lacZ gene driven off an internal rat beta-actin promoter. Beta-galactosidase-positive cells were identified in all embryonic tissues including inner cell mass, epiblast, mesoderm, endoderm and definitive ectoderm. In contrast, embryos infected with a MoMuLV-based vector expressing the lacZ gene driven off the viral LTR showed beta-galactosidase-positive cells only in mesoderm and definitive ectoderm. We conclude that permissiveness to transcriptional activity of the LTR is acquired immediately upon differentiation of epiblast during gastrulation of the mouse embryo.

Recombination between feline leukemia virus subgroup B or C and endogenous env elements alters the in vitro biological activities of the viruses.

1992 ◽  
Vol 66 (6) ◽  
pp. 3976 ◽  
Author(s):  
R Pandey ◽  
A K Ghosh ◽  
D V Kumar ◽  
B A Bachman ◽  
D Shibata ◽  
...  
Keyword(s):  
Biological Activities ◽  
Leukemia Virus ◽  
Feline Leukemia Virus

scholarly journals Modulation of Viral Programmed Ribosomal Frameshifting and Stop Codon Readthrough by the Host Restriction Factor Shiftless

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1230
Author(s):  
Sawsan Napthine ◽  
Chris H. Hill ◽  
Holly C. M. Nugent ◽  
Ian Brierley
Keyword(s):  
Rna Binding ◽  
Mutational Analysis ◽  
Stop Codon ◽  
Leukemia Virus ◽  
Size Exclusion ◽  
Human Immunodeficiency Virus Replication ◽  
Mobility Shift ◽  
Ribosomal Frameshifting ◽  
Stop Codon Readthrough

The product of the interferon-stimulated gene C19orf66, Shiftless (SHFL), restricts human immunodeficiency virus replication through downregulation of the efficiency of the viral gag/pol frameshifting signal. In this study, we demonstrate that bacterially expressed, purified SHFL can decrease the efficiency of programmed ribosomal frameshifting in vitro at a variety of sites, including the RNA pseudoknot-dependent signals of the coronaviruses IBV, SARS-CoV and SARS-CoV-2, and the protein-dependent stimulators of the cardioviruses EMCV and TMEV. SHFL also reduced the efficiency of stop-codon readthrough at the murine leukemia virus gag/pol signal. Using size-exclusion chromatography, we confirm the binding of the purified protein to mammalian ribosomes in vitro. Finally, through electrophoretic mobility shift assays and mutational analysis, we show that expressed SHFL has strong RNA binding activity that is necessary for full activity in the inhibition of frameshifting, but shows no clear specificity for stimulatory RNA structures.

scholarly journals Androgenic-Induced Transposable Elements Dependent Sequence Variation in Barley

2021 ◽  
Vol 22 (13) ◽  
pp. 6783
Author(s):  
Renata Orłowska ◽  
Katarzyna A. Pachota ◽  
Wioletta M. Dynkowska ◽  
Agnieszka Niedziela ◽  
Piotr T. Bednarek
Keyword(s):  
Dna Methylation ◽  
Transposable Elements ◽  
Dna Sequence ◽  
Sequence Variation ◽  
Nuclear Dna ◽  
Point Mutations ◽  
Mobile Elements ◽  
Dna Demethylation ◽  
Plant Genome

A plant genome usually encompasses different families of transposable elements (TEs) that may constitute up to 85% of nuclear DNA. Under stressful conditions, some of them may activate, leading to sequence variation. In vitro plant regeneration may induce either phenotypic or genetic and epigenetic changes. While DNA methylation alternations might be related, i.e., to the Yang cycle problems, DNA pattern changes, especially DNA demethylation, may activate TEs that could result in point mutations in DNA sequence changes. Thus, TEs have the highest input into sequence variation (SV). A set of barley regenerants were derived via in vitro anther culture. High Performance Liquid Chromatography (RP-HPLC), used to study the global DNA methylation of donor plants and their regenerants, showed that the level of DNA methylation increased in regenerants by 1.45% compared to the donors. The Methyl-Sensitive Transposon Display (MSTD) based on methylation-sensitive Amplified Fragment Length Polymorphism (metAFLP) approach demonstrated that, depending on the selected elements belonging to the TEs family analyzed, varying levels of sequence variation were evaluated. DNA sequence contexts may have a different impact on SV generated by distinct mobile elements belonged to various TE families. Based on the presented study, some of the selected mobile elements contribute differently to TE-related SV. The surrounding context of the TEs DNA sequence is possibly important here, and the study explained some part of SV related to those contexts.

scholarly journals Biochemical Characterization, Specificity and Inhibition Studies of HTLV-1, HTLV-2, and HTLV-3 Proteases

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 127
Author(s):  
Norbert Kassay ◽  
János András Mótyán ◽  
Krisztina Matúz ◽  
Mária Golda ◽  
József Tőzsér
Keyword(s):  
T Cell ◽  
Biochemical Characterization ◽  
Leukemia Virus ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Cell Leukemia Virus Type ◽  
Adult T Cell Leukemia ◽  
Human T Cell ◽  
T Cell Leukemia Virus

The human T-lymphotropic viruses (HTLVs) are causative agents of severe diseases including adult T-cell leukemia. Similar to human immunodeficiency viruses (HIVs), the viral protease (PR) plays a crucial role in the viral life-cycle via the processing of the viral polyproteins. Thus, it is a potential target of anti-retroviral therapies. In this study, we performed in vitro comparative analysis of human T-cell leukemia virus type 1, 2, and 3 (HTLV-1, -2, and -3) proteases. Amino acid preferences of S4 to S1′ subsites were studied by using a series of synthetic oligopeptide substrates representing the natural and modified cleavage site sequences of the proteases. Biochemical characteristics of the different PRs were also determined, including catalytic efficiencies and dependence of activity on pH, temperature, and ionic strength. We investigated the effects of different HIV-1 PR inhibitors (atazanavir, darunavir, DMP-323, indinavir, ritonavir, and saquinavir) on enzyme activities, and inhibitory potentials of IB-268 and IB-269 inhibitors that were previously designed against HTLV-1 PR. Comparative biochemical analysis of HTLV-1, -2, and -3 PRs may help understand the characteristic similarities and differences between these enzymes in order to estimate the potential of the appearance of drug-resistance against specific HTLV-1 PR inhibitors.

scholarly journals New Quinoxaline Derivatives as Dual Pim-1/2 Kinase Inhibitors: Design, Synthesis and Biological Evaluation

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 867
Author(s):  
Bruno Oyallon ◽  
Marie Brachet-Botineau ◽  
Cédric Logé ◽  
Thomas Robert ◽  
Stéphane Bach ◽  
...  
Keyword(s):  
Colorectal Carcinoma ◽  
Cancer Progression ◽  
Kinase Inhibitors ◽  
Integration Site ◽  
Leukemia Virus ◽  
Biological Evaluation ◽  
Design Synthesis ◽  
Proviral Integration Site ◽  
Quinoxaline Derivatives

Proviral integration site for Moloney murine leukemia virus (Pim)-1/2 kinase overexpression has been identified in a variety of hematologic (e.g., multiple myeloma or acute myeloid leukemia (AML)) and solid (e.g., colorectal carcinoma) tumors, playing a key role in cancer progression, metastasis, and drug resistance, and is linked to poor prognosis. These kinases are thus considered interesting targets in oncology. We report herein the design, synthesis, structure–activity relationships (SAR) and in vitro evaluations of new quinoxaline derivatives, acting as dual Pim1/2 inhibitors. Two lead compounds (5c and 5e) were then identified, as potent submicromolar Pim-1 and Pim-2 inhibitors. These molecules were also able to inhibit the growth of the two human cell lines, MV4-11 (AML) and HCT-116 (colorectal carcinoma), expressing high endogenous levels of Pim-1/2 kinases.

scholarly journals Effect of Small Polyanions on In Vitro Assembly of Selected Members of Alpha-, Beta- and Gammaretroviruses

Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 129
Author(s):  
Alžběta Dostálková ◽  
Barbora Vokatá ◽  
Filip Kaufman ◽  
Pavel Ulbrich ◽  
Tomáš Ruml ◽  
...  
Keyword(s):  
Equine Infectious Anemia Virus ◽  
Electron Tomography ◽  
Leukemia Virus ◽  
Virus Like Particles ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Anemia Virus ◽  
Immature Virus ◽  
Hiv 1

The assembly of a hexameric lattice of retroviral immature particles requires the involvement of cell factors such as proteins and small molecules. A small, negatively charged polyanionic molecule, myo-inositol hexaphosphate (IP6), was identified to stimulate the assembly of immature particles of HIV-1 and other lentiviruses. Interestingly, cryo-electron tomography analysis of the immature particles of two lentiviruses, HIV-1 and equine infectious anemia virus (EIAV), revealed that the IP6 binding site is similar. Based on this amino acid conservation of the IP6 interacting site, it is presumed that the assembly of immature particles of all lentiviruses is stimulated by IP6. Although this specific region for IP6 binding may be unique for lentiviruses, it is plausible that other retroviral species also recruit some small polyanion to facilitate the assembly of their immature particles. To study whether the assembly of retroviruses other than lentiviruses can be stimulated by polyanionic molecules, we measured the effect of various polyanions on the assembly of immature virus-like particles of Rous sarcoma virus (RSV), a member of alpharetroviruses, Mason-Pfizer monkey virus (M-PMV) representative of betaretroviruses, and murine leukemia virus (MLV), a member of gammaretroviruses. RSV, M-PMV and MLV immature virus-like particles were assembled in vitro from truncated Gag molecules and the effect of selected polyanions, myo-inostol hexaphosphate, myo-inositol, glucose-1,6-bisphosphate, myo-inositol hexasulphate, and mellitic acid, on the particles assembly was quantified. Our results suggest that the assembly of immature particles of RSV and MLV was indeed stimulated by the presence of myo-inostol hexaphosphate and myo-inositol, respectively. In contrast, no effect on the assembly of M-PMV as a betaretrovirus member was observed.

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