scholarly journals A Genome-Wide Analysis of RNA Pseudoknots That Stimulate Efficient −1 Ribosomal Frameshifting or Readthrough in Animal Viruses

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Xiaolan Huang ◽  
Qiang Cheng ◽  
Zhihua Du
Keyword(s):  
Large Scale ◽  
Stop Codon ◽  
Ribosomal Frameshifting ◽  
Viral Genomes ◽  
Genome Wide Analysis ◽  
Genome Wide ◽  
A Genome ◽  
Rna Pseudoknots ◽  
Rna Pseudoknot ◽  
Stop Codon Readthrough

Programmed −1 ribosomal frameshifting (PRF) and stop codon readthrough are two translational recoding mechanisms utilized by some RNA viruses to express their structural and enzymatic proteins at a defined ratio. Efficient recoding usually requires an RNA pseudoknot located several nucleotides downstream from the recoding site. To assess the strategic importance of the recoding pseudoknots, we have carried out a large scale genome-wide analysis in which we used an in-house developed program to detect all possible H-type pseudoknots within the genomic mRNAs of 81 animal viruses. Pseudoknots are detected downstream from ~85% of the recoding sites, including many previously unknown pseudoknots. ~78% of the recoding pseudoknots are the most stable pseudoknot within the viral genomes. However, they are not as strong as some designed pseudoknots that exhibit roadblocking effect on the translating ribosome. Strong roadblocking pseudoknots are not detected within the viral genomes. These results indicate that the decoding pseudoknots have evolved to possess optimal stability for efficient recoding. We also found that the sequence at thegag-polframeshift junction of HIV1 harbors potential elaborated pseudoknots encompassing the frameshift site. A novel mechanism is proposed for possible involvement of the elaborated pseudoknots in the HIV1 PRF event.

scholarly journals Transcriptome-wide investigation of stop codon readthrough in Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Kotchaphorn Mangkalaphiban ◽  
Feng He ◽  
Robin Ganesan ◽  
Chan Wu ◽  
Richard Baker ◽  
...  
Keyword(s):  
Stop Codon ◽  
Regulatory Elements ◽  
Ribosome Profiling ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Coding Region ◽  
Genome Wide ◽  
A Genome ◽  
Stop Codon Readthrough

Translation of mRNA into a polypeptide is terminated when the release factor eRF1 recognizes a UAA, UAG, or UGA stop codon in the ribosomal A site and stimulates nascent peptide release. However, stop codon readthrough can occur when a near-cognate tRNA outcompetes eRF1 in decoding the stop codon, resulting in the continuation of the elongation phase of protein synthesis. At the end of a conventional mRNA coding region, readthrough allows translation into the mRNA 3′-UTR. Previous studies with reporter systems have shown that the efficiency of termination or readthrough is modulated by cis-acting elements other than stop codon identity, including two nucleotides 5′ of the stop codon, six nucleotides 3′ of the stop codon in the ribosomal mRNA channel, and stem-loop structures in the mRNA 3′-UTR. It is unknown whether these elements are important at a genome-wide level and whether other mRNA features proximal to the stop codon significantly affect termination and readthrough efficiencies in vivo. Accordingly, we carried out ribosome profiling analyses of yeast cells expressing wild-type or temperature-sensitive eRF1 and developed bioinformatics strategies to calculate readthrough efficiency, and to identify mRNA and peptide features which influence that efficiency. We found that the stop codon (nt +1 to +3), the nucleotide after it (nt +4), the codon in the P site (nt -3 to -1), and 3′-UTR length are the most influential features in the control of readthrough efficiency, while nts +5 to +9 and mRNA secondary structure in the 3′-UTR had milder effects. Additionally, we found low readthrough genes to have shorter 3′-UTRs compared to high readthrough genes in cells with thermally inactivated eRF1, while this trend was reversed in wild-type cells. Together, our results demonstrated the general roles of known regulatory elements in genome-wide regulation and identified several new mRNA or peptide features affecting the efficiency of translation termination and readthrough.

scholarly journals Transcriptome-wide investigation of stop codon readthrough in Saccharomyces cerevisiae

PLoS Genetics ◽  
2021 ◽  
Vol 17 (4) ◽  
pp. e1009538
Author(s):  
Kotchaphorn Mangkalaphiban ◽  
Feng He ◽  
Robin Ganesan ◽  
Chan Wu ◽  
Richard Baker ◽  
...  
Keyword(s):  
Stop Codon ◽  
Regulatory Elements ◽  
Ribosome Profiling ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Coding Region ◽  
Genome Wide ◽  
A Genome ◽  
Stop Codon Readthrough

Translation of mRNA into a polypeptide is terminated when the release factor eRF1 recognizes a UAA, UAG, or UGA stop codon in the ribosomal A site and stimulates nascent peptide release. However, stop codon readthrough can occur when a near-cognate tRNA outcompetes eRF1 in decoding the stop codon, resulting in the continuation of the elongation phase of protein synthesis. At the end of a conventional mRNA coding region, readthrough allows translation into the mRNA 3’-UTR. Previous studies with reporter systems have shown that the efficiency of termination or readthrough is modulated by cis-acting elements other than stop codon identity, including two nucleotides 5’ of the stop codon, six nucleotides 3’ of the stop codon in the ribosomal mRNA channel, and stem-loop structures in the mRNA 3’-UTR. It is unknown whether these elements are important at a genome-wide level and whether other mRNA features proximal to the stop codon significantly affect termination and readthrough efficiencies in vivo. Accordingly, we carried out ribosome profiling analyses of yeast cells expressing wild-type or temperature-sensitive eRF1 and developed bioinformatics strategies to calculate readthrough efficiency, and to identify mRNA and peptide features which influence that efficiency. We found that the stop codon (nt +1 to +3), the nucleotide after it (nt +4), the codon in the P site (nt -3 to -1), and 3’-UTR length are the most influential features in the control of readthrough efficiency, while nts +5 to +9 had milder effects. Additionally, we found low readthrough genes to have shorter 3’-UTRs compared to high readthrough genes in cells with thermally inactivated eRF1, while this trend was reversed in wild-type cells. Together, our results demonstrated the general roles of known regulatory elements in genome-wide regulation and identified several new mRNA or peptide features affecting the efficiency of translation termination and readthrough.

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 Energetic Evolution of Cellular Transportomes

2017 ◽  
Author(s):  
Behrooz Darbani ◽  
Douglas B. Kell ◽  
Irina Borodina
Keyword(s):  
Ion Channels ◽  
Bacterial Species ◽  
Living Cells ◽  
Energetic Efficiency ◽  
Cellular Functions ◽  
Transporter Proteins ◽  
Genome Wide Analysis ◽  
Solute Carriers ◽  
Genome Wide ◽  
A Genome

ABSTRACTTransporter proteins mediate the translocation of substances across the membranes of living cells. We performed a genome-wide analysis of the compositional reshaping of cellular transporters (the transportome) across the kingdoms of bacteria, archaea, and eukarya. We show that the transportomes of eukaryotes evolved strongly towards a higher energetic efficiency, as ATP-dependent transporters diminished and secondary transporters and ion channels proliferated. This change has likely been important in the development of tissues performing energetically costly cellular functions. The transportome analysis also indicated seven bacterial species, includingNeorickettsia risticiiandNeorickettsia sennetsu, as likely origins of the mitochondrion in eukaryotes, due to the restricted presence therein of clear homologues of modern mitochondrial solute carriers.

scholarly journals Comprehensive Genome-Wide Analysis of The Catalase Enzyme Toolbox In Potato (Solanum Tuberosum L.)

2021 ◽  
Author(s):  
Rania Jbir Koubaa ◽  
Mariem Ayadi ◽  
Mohamed Najib Saidi ◽  
Safa Charfeddine ◽  
Radhia Gargouri Bouzid ◽  
...  
Keyword(s):  
Stress Responses ◽  
Expression Profiling ◽  
Phylogenetic Trees ◽  
Solanum Tuberosum L ◽  
Potato Cultivar ◽  
Promoter Sequence ◽  
3D Protein Structure ◽  
Genome Wide Analysis ◽  
Genome Wide ◽  
A Genome

Abstract As antioxidant enzymes, catalase (CAT) protects organisms from oxidative stress via the production of reactive oxygen species (ROS). These enzymes play important roles in diverse biological processes. However, little is known about the CAT genes in potato plants despite its important economical rank of this crop in the world. Yet, abiotic and biotic stresses severely hinder growth and development of the plants which affects the production and quality of the crop. To define the possible roles of CAT genes under various stresses, a genome-wide analysis of CAT gene family has been performed in potato plant.In this study, the StCAT gene’s structure, secondary and 3D protein structure, physicochemical properties, synteny analysis, phylogenetic tree and also expression profiling under various developmental and environmental cues were predicted using bioinformatics tools. The expression analysis by RT-PCR was performed using commercial potato cultivar. Three genes encoding StCAT that code for three proteins each of size 492 aa, interrupted by seven introns have been identified in potatoes. StCAT proteins were found to be localized in the peroxisome which is judged as the main H2O2 cell production site during different processes. Many regulating cis-elements related to stress responses and plant hormones signaling were found in the promoter sequence of each gene. The analysis of motifs and phylogenetic trees showed that StCAT are closer to their homologous in S. lycopersicum and share a 41% – 95% identity with other plants’ CATs. Expression profiling revealed that StCAT1 is the constitutively expressive member; while StCAT2 and StCAT3 are the stress-responsive members.

scholarly journals A Genome‐Wide Analysis of Placental Epigenetic Markers in Response to Maternal Choline Supplementation

2017 ◽  
Vol 31 (S1) ◽  
Author(s):  
Sze Ting (Cecilia) Kwan ◽  
Minghui Wang ◽  
Julia H King ◽  
Jian Yan ◽  
Xinyin Jiang ◽  
...  
Keyword(s):  
Epigenetic Markers ◽  
Genome Wide Analysis ◽  
Genome Wide ◽  
A Genome
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