scholarly journals Unique Temperature-Sensitive Defect in Vaccinia Virus Morphogenesis Maps to a Single Nucleotide Substitution in the A30L Gene

2001 ◽  
Vol 75 (22) ◽  
pp. 11222-11226 ◽  
Author(s):  
Patricia Szajner ◽  
Andrea S. Weisberg ◽  
Bernard Moss
Keyword(s):  
Vaccinia Virus ◽  
Nucleotide Substitution ◽  
Elevated Temperatures ◽  
Base Change ◽  
Temperature Sensitive ◽  
Single Nucleotide ◽  
Reading Frame ◽  
Genetic Lesion ◽  
Virus Morphogenesis ◽  
Single Base Change

ABSTRACT Marker rescue experiments demonstrated that the genetic lesion of a previously isolated vaccinia virus temperature-sensitive mutant which forms multilayered envelope structures with lucent interiors and foci of viroplasm with dense centers mapped to the A30L open reading frame. A single base change, resulting in a nonconservative Ser-to-Phe substitution at residue 17, was associated with degradation of the A30L protein at elevated temperatures.

scholarly journals A gain-of-function single nucleotide variant creates a new promoter which acts as an orientation-dependent enhancer-blocker

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yavor K. Bozhilov ◽  
Damien J. Downes ◽  
Jelena Telenius ◽  
A. Marieke Oudelaar ◽  
Emmanuel N. Olivier ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genetic Diseases ◽  
Regulatory Elements ◽  
Base Change ◽  
Dependent Manner ◽  
Globin Genes ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Super Enhancer ◽  
Single Base Change

AbstractMany single nucleotide variants (SNVs) associated with human traits and genetic diseases are thought to alter the activity of existing regulatory elements. Some SNVs may also create entirely new regulatory elements which change gene expression, but the mechanism by which they do so is largely unknown. Here we show that a single base change in an otherwise unremarkable region of the human α-globin cluster creates an entirely new promoter and an associated unidirectional transcript. This SNV downregulates α-globin expression causing α-thalassaemia. Of note, the new promoter lying between the α-globin genes and their associated super-enhancer disrupts their interaction in an orientation-dependent manner. Together these observations show how both the order and orientation of the fundamental elements of the genome determine patterns of gene expression and support the concept that active genes may act to disrupt enhancer-promoter interactions in mammals as in Drosophila. Finally, these findings should prompt others to fully evaluate SNVs lying outside of known regulatory elements as causing changes in gene expression by creating new regulatory elements.

scholarly journals Cloning of an Avian Adeno-Associated Virus (AAAV) and Generation of Recombinant AAAV Particles

2003 ◽  
Vol 77 (12) ◽  
pp. 6799-6810 ◽  
Author(s):  
Ioannis Bossis ◽  
John A. Chiorini
Keyword(s):  
Nucleotide Substitution ◽  
Amino Acid Level ◽  
The Other ◽  
Transduction Efficiency ◽  
Entire Genome ◽  
Single Nucleotide ◽  
Adeno Associated Virus ◽  
Reading Frame ◽  
Palindromic Structure ◽  
The Relationship

ABSTRACT Recent studies have proposed that adeno-associated viruses (AAVs) are not evolutionarily linked to other mammalian autonomous parvoviruses but are more closely linked to the autonomous parvoviruses of birds. To better understand the relationship between primate and avian AAVs (AAAVs), we cloned and sequenced the genome of an AAAV (ATCC VR-865) and generated recombinant AAAV particles. The genome of AAAV is 4,694 nucleotides in length and has organization similar to that of other AAVs. The entire genome of AAAV displays 56 to 65% identity at the nucleotide level with the other known AAVs. The AAAV genome has inverted terminal repeats of 142 nucleotides, with the first 122 forming the characteristic T-shaped palindromic structure. The putative Rep-binding element consists of a tandem (GAGY)4 repeat, and the putative terminal resolution site (trs), CCGGT/CG, contains a single nucleotide substitution relative to the AAV2 trs. The Rep open reading frame of AAAV displays 50 to 54% identity at the amino acid level with the other AAVs, with most of the diversity clustered at the carboxyl and amino termini. Comparison of the capsid proteins of AAAV and the primate dependoviruses indicate that divergent regions are localized to surface-exposed loops. Despite these sequence differences, we were able to produce recombinant AAAV particles carrying a lacZ reporter gene by cotransfection in 293T cells and were able to examine transduction efficiency in both chicken primary cells and several cell lines. Our findings indicate that AAAV is the most divergent AAV described to date but maintains all the characteristics unique to the genera of dependovirus.

scholarly journals Evidence for an Essential Catalytic Role of the F10 Protein Kinase in Vaccinia Virus Morphogenesis

2004 ◽  
Vol 78 (1) ◽  
pp. 257-265 ◽  
Author(s):  
Patricia Szajner ◽  
Andrea S. Weisberg ◽  
Bernard Moss
Keyword(s):  
Protein Kinase ◽  
Vaccinia Virus ◽  
Early Stage ◽  
Single Amino Acid ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Membrane Formation ◽  
Virus Morphogenesis ◽  
Catalytic Role

ABSTRACT Temperature-sensitive mutants of vaccinia virus, with genetic changes that map to the open reading frame encoding the F10 protein kinase, exhibit a defect at an early stage of viral morphogenesis. To further study the role of the enzyme, we constructed recombinant vaccinia virus vF10V5i, which expresses inducible V5 epitope-tagged F10 and is dependent on a chemical inducer for plaque formation and replication. In the absence of inducer, viral membrane formation was delayed and crescents and occasional immature forms were detected only late in infection. When the temperature was raised from 37 to 39°C, the block in membrane formation persisted throughout the infection. The increased stringency may be explained by a mild temperature sensitivity of the wild-type F10 kinase, which reduced the activity of the very small amount expressed in the absence of inducer, or by the thermolability of an unphosphorylated kinase substrate or uncomplexed F10-interacting protein. Further analyses demonstrated that tyrosine and threonine phosphorylation of the A17 membrane component was inhibited in the absence of inducer. The phosphorylation defect could be overcome by transfection of plasmids that express wild-type F10, but not by plasmids that express F10 with single amino acid substitutions that abolished catalytic activity. Although the mutated forms of F10 were stable and concentrated in viral factories, only the wild-type protein complemented the assembly and replication defects of vF10V5i in the absence of inducer. These studies provide evidence for an essential catalytic role of the F10 kinase in vaccinia virus morphogenesis.

scholarly journals The Escherichia coli rpoS-Dependent htrC Gene Is Not Involved in the Heat Shock Response

2006 ◽  
Vol 188 (23) ◽  
pp. 8317-8320
Author(s):  
Zubin Thacker ◽  
Elise Darmon ◽  
France Keppel ◽  
Millicent Masters
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Elevated Temperatures ◽  
Open Reading Frame ◽  
Temperature Sensitive ◽  
Early Stationary Phase ◽  
Reading Frame ◽  
Enhanced Expression ◽  
K 12 ◽  
Distinctive Phenotype

ABSTRACT We found that a new mutant with a deletion/replacement of the Escherichia coli K-12 htrC gene, a gene previously reported to be required for growth at elevated temperatures, is not temperature sensitive. Furthermore, the original mutants, kindly provided by the original authors, although temperature sensitive, do not have mutations in the open reading frame designated htrC. We found that htrC requires RpoS for enhanced expression in the early stationary phase and is expressed at very low levels until then. The growth of our htrC mutant slowed during the early stationary phase, and the mutant was replaced by its parent in mixed cultures. Since we cannot assign a function or distinctive phenotype to htrC, we suggest that this open reading frame should be given a positional designation, yjaZ, until a specific function is identified.

scholarly journals Effects of a Temperature Sensitivity Mutation in the J1R Protein Component of a Complex Required for Vaccinia Virus Assembly

2005 ◽  
Vol 79 (13) ◽  
pp. 8046-8056 ◽  
Author(s):  
Wen-Ling Chiu ◽  
Patricia Szajner ◽  
Bernard Moss ◽  
Wen Chang
Keyword(s):  
Vaccinia Virus ◽  
Virus Assembly ◽  
Terminal Region ◽  
Temperature Sensitive ◽  
Loss Of Function ◽  
Wild Type ◽  
Reading Frame ◽  
Infected Cells ◽  
The Stability ◽  
Virus C

ABSTRACT Vaccinia virus J1R protein is required for virion morphogenesis (W. L. Chiu and W. Chang, J. Virol. 76:9575-9587, 2002). In this work, we further characterized the J1R protein of wild-type vaccinia virus and compared it with the protein encoded by the temperature-sensitive mutant virus Cts45. The mutant Cts45 was found to contain a Pro-to-Ser substitution at residue 132 of the J1R open reading frame, which is responsible for a loss-of-function phenotype. The half-life of the J1R-P132S mutant protein was comparable at both 31 and 39°C, indicating that the P132S mutation did not affect the stability of the J1R protein. We also showed that the J1R protein interacts with itself in the virus-infected cells. The N-terminal region of the J1R protein, amino acids (aa) 1 to 77, interacted with the C-terminal region, aa 84 to 153, and the P132 mutation did not abolish this interaction, as determined by two-hybrid analysis. Furthermore, we demonstrated that J1R protein is part of a viral complex containing the A30L, G7L, and F10L proteins in virus-infected cells. In immunofluorescence analyses, wild-type J1R protein colocalized with the A30L, G7L, and F10L proteins in virus-infected cells but the loss-of-function P132 mutant did not. Furthermore, without a functional J1R protein, rapid degradation of A30L and the 15-kDa forms of the G7L and F10L proteins was observed in cells infected with Cts45 at 39°C. This study thus demonstrated the importance of the J1R protein in the formation of a viral assembly complex required for morphogenesis.

scholarly journals Genetic Variant in 3’ Untranslated Region of the Mouse Pycard Gene Regulates Inflammasome Activity

2021 ◽  
Author(s):  
Brian Ritchey ◽  
Qimin Hai ◽  
Juying Han ◽  
John Barnard ◽  
Jonathan D. Smith
Keyword(s):  
Mrna Stability ◽  
Untranslated Region ◽  
Embryonic Stem ◽  
Adaptor Protein ◽  
Base Change ◽  
Single Nucleotide ◽  
Single Base Change ◽  
Trait Locus ◽  
Locus Mapping ◽  
Inflammasome Activity

AbstractQuantitative trait locus mapping for interleukin-1β release after inflammasome priming and activation was performed on bone marrow-derived macrophages (BMDM) from an AKRxDBA/2 strain intercross. The strongest associated locus mapped very close to the Pycard gene on chromosome 7, which codes for the inflammasome adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC). The DBA/2 and AKR Pycard genes only differ at single nucleotide polymorphism (SNP) in their 3’ untranslated region (UTR). DBA/2 vs. AKR BMDM had increased levels of Pycard mRNA expression and ASC protein, and increased inflammasome speck formation, which was associated with increased Pycard mRNA stability without an increased transcription rate. CRIPSR/Cas9 gene editing was performed on DBA/2 embryonic stem cells to change the Pycard 3’UTR SNP from the DBA/2 to the AKR allele. This single base change significantly reduced Pycard expression and inflammasome activity after cells were differentiated into macrophages due to reduced Pycard mRNA stability.

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