Dinucleotide analogues of the mRNA cap that enhance translational efficiency

2005 ◽  
Author(s):  
Jacek Jemielity ◽  
Janusz Stępiński ◽  
Joanna Zuberek ◽  
Ewa Grudzien ◽  
Magdalena Lewdorowicz ◽  
...  
Keyword(s):  
Translational Efficiency

scholarly journals Enhanced Transcriptomic Resilience following Increased Alternative Splicing and Differential Isoform Production between Air Pollution Conurbations

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 959
Author(s):  
Shengkai Pan ◽  
Xiaokai Feng ◽  
Daniel Pass ◽  
Rachel A. Adams ◽  
Yusong Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Alternative Splicing ◽  
Real Life ◽  
Chronic Obstructive ◽  
Translational Efficiency ◽  
Ambient Particulate Matter ◽  
Obstructive Pulmonary Disease ◽  
Adverse Health Outcomes ◽  
Membrane Bound ◽  
Migration Capacity

Adverse health outcomes caused by ambient particulate matter (PM) pollution occur in a progressive process, with neutrophils eliciting inflammation or pathogenesis. We investigated the toxico-transcriptomic mechanisms of PM in real-life settings by comparing healthy residents living in Beijing and Chengde, the opposing ends of a well-recognised air pollution (AP) corridor in China. Beijing recruits (BRs) uniquely expressed ~12,000 alternative splicing (AS)-derived transcripts, largely elevating the proportion of transcripts significantly correlated with PM concentration. BRs expressed PM-associated isoforms (PMAIs) of PFKFB3 and LDHA, encoding enzymes responsible for stimulating and maintaining glycolysis. PMAIs of PFKFB3 featured different COOH-terminals, targeting PFKFB3 to different sub-cellular functional compartments and stimulating glycolysis. PMAIs of LDHA have longer 3′UTRs relative to those expressed in Chengde recruits (CRs), allowing glycolysis maintenance by enhancing LDHA mRNA stability and translational efficiency. PMAIs were directly regulated by different HIF-1A and HIF-1B isoforms. BRs expressed more non-functional Fas isoforms, and a resultant reduction of intact Fas proportion is expected to inhibit the transmission of apoptotic signals and prolong neutrophil lifespan. BRs expressed both membrane-bound and soluble IL-6R isoforms instead of only one in CRs. The presence of both IL-6R isoforms suggested a higher migration capacity of neutrophils in BRs. PMAIs of HIF-1A and PFKFB3 were downregulated in Chronic Obstructive Pulmonary Disease patients compared with BRs, implying HIF-1 mediated defective glycolysis may mediate neutrophil dysfunction. PMAIs could explain large variances of different phenotypes, highlighting their potential application as biomarkers and therapeutic targets in PM-induced diseases, which remain poorly elucidated.

scholarly journals Upregulation of 5′-terminal oligopyrimidine mRNA translation upon loss of the ARF tumor suppressor

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kyle A. Cottrell ◽  
Ryan C. Chiou ◽  
Jason D. Weber
Keyword(s):  
Protein Synthesis ◽  
Tumor Cells ◽  
Ribosomal Proteins ◽  
Human Cancer ◽  
Mrna Translation ◽  
Ribosome Profiling ◽  
Translational Efficiency ◽  
Gene Encoding ◽  
Terminal Oligopyrimidine ◽  
Ribosome Export

AbstractTumor cells require nominal increases in protein synthesis in order to maintain high proliferation rates. As such, tumor cells must acquire enhanced ribosome production. How the numerous mutations in tumor cells ultimately achieve this aberrant production is largely unknown. The gene encoding ARF is the most commonly deleted gene in human cancer. ARF plays a significant role in regulating ribosomal RNA synthesis and processing, ribosome export into the cytoplasm, and global protein synthesis. Utilizing ribosome profiling, we show that ARF is a major suppressor of 5′-terminal oligopyrimidine mRNA translation. Genes with increased translational efficiency following loss of ARF include many ribosomal proteins and translation factors. Knockout of p53 largely phenocopies ARF loss, with increased protein synthesis and expression of 5′-TOP encoded proteins. The 5′-TOP regulators eIF4G1 and LARP1 are upregulated in Arf- and p53-null cells.

scholarly journals Codon usage bias and environmental adaptation in microbial organisms

2021 ◽  
Author(s):  
Davide Arella ◽  
Maddalena Dilucca ◽  
Andrea Giansanti
Keyword(s):  
Codon Usage ◽  
Codon Usage Bias ◽  
Pathogenic Bacteria ◽  
Large Scale ◽  
Synonymous Codon ◽  
Principal Component ◽  
Gene Copy ◽  
Phenotypic Traits ◽  
Translational Efficiency ◽  
Microbial Organisms

AbstractIn each genome, synonymous codons are used with different frequencies; this general phenomenon is known as codon usage bias. It has been previously recognised that codon usage bias could affect the cellular fitness and might be associated with the ecology of microbial organisms. In this exploratory study, we investigated the relationship between codon usage bias, lifestyles (thermophiles vs. mesophiles; pathogenic vs. non-pathogenic; halophilic vs. non-halophilic; aerobic vs. anaerobic and facultative) and habitats (aquatic, terrestrial, host-associated, specialised, multiple) of 615 microbial organisms (544 bacteria and 71 archaea). Principal component analysis revealed that species with given phenotypic traits and living in similar environmental conditions have similar codon preferences, as represented by the relative synonymous codon usage (RSCU) index, and similar spectra of tRNA availability, as gauged by the tRNA gene copy number (tGCN). Moreover, by measuring the average tRNA adaptation index (tAI) for each genome, an index that can be associated with translational efficiency, we observed that organisms able to live in multiple habitats, including facultative organisms, mesophiles and pathogenic bacteria, are characterised by a reduced translational efficiency, consistently with their need to adapt to different environments. Our results show that synonymous codon choices might be under strong translational selection, which modulates the choice of the codons to differently match tRNA availability, depending on the organism’s lifestyle needs. To our knowledge, this is the first large-scale study that examines the role of codon bias and translational efficiency in the adaptation of microbial organisms to the environment in which they live.

scholarly journals The 5' and 3' untranslated regions of satellite tobacco necrosis virus RNA affect translational efficiency and dependence on a 5' cap structure

1993 ◽  
Vol 268 (13) ◽  
pp. 9504-9510
Author(s):  
R.T. Timmer ◽  
L.A. Benkowski ◽  
D. Schodin ◽  
S.R. Lax ◽  
A.M. Metz ◽  
...  
Keyword(s):  
Untranslated Regions ◽  
Tobacco Necrosis Virus ◽  
Translational Efficiency ◽  
Necrosis Virus ◽  
Virus Rna

How Optimized Is the Translational Machinery in Escherichia coli, Salmonella typhimurium and Saccharomyces cerevisiae?

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Xuhua Xia
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Salmonella Typhimurium ◽  
Codon Usage ◽  
Translational Efficiency ◽  
Square Root ◽  
Translational Machinery ◽  
Mutual Adaptation ◽  
Trna Species

Abstract The optimization of the translational machinery in cells requires the mutual adaptation of codon usage and tRNA concentration, and the adaptation of tRNA concentration to amino acid usage. Two predictions were derived based on a simple deterministic model of translation which assumes that elongation of the peptide chain is rate-limiting. The highest translational efficiency is achieved when the codon recognized by the most abundant tRNA reaches the maximum frequency. For each codon family, the tRNA concentration is optimally adapted to codon usage when the concentration of different tRNA species matches the square-root of the frequency of their corresponding synonymous codons. When tRNA concentration and codon usage are well adapted to each other, the optimal content of all tRNA species carrying the same amino acid should match the square-root of the frequency of the amino acid. These predictions are examined against empirical data from Escherichia coli, Salmonella typhimurium, and Saccharomyces cerevisiae.

Insulin-like growth factor I accelerates protein synthesis in skeletal muscle during sepsis

1995 ◽  
Vol 269 (5) ◽  
pp. E977-E981 ◽  
Author(s):  
C. V. Jurasinski ◽  
T. C. Vary
Keyword(s):  
Protein Synthesis ◽  
Growth Factor ◽  
Peptide Chain ◽  
Translational Efficiency ◽  
Insulin Like Growth Factor ◽  
Recombinant Human Insulin ◽  
Chain Initiation ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Sepsis causes an inhibition of protein synthesis in gastrocnemius that is resistant to the anabolic effects of insulin. The purpose of the present studies was to investigate the effect of recombinant human insulin-like growth factor I (IGF-I) on protein synthesis during a 30-min perfusion of the isolated rat hindlimb from septic rats. Inclusion of IGF-I (1 or 10 nM) in the perfusate stimulated protein synthesis in gastrocnemius of septic rats 2.5-fold and restored rates of protein synthesis to those observed in control rats. The stimulation of protein synthesis did not result from an increase in the RNA content but was correlated with a 2.5-fold increase in the translational efficiency. The enhanced translational efficiency was accompanied by a 33 and 55% decrease in the abundance of free 40S and 60S ribosomal subunits, respectively, indicating that IGF-I accelerated peptide-chain initiation relative to elongation/termination. These studies provide evidence that IGF-I can accelerate protein synthesis in gastrocnemius during chronic sepsis by reversing the sepsis-induced inhibition of peptide-chain initiation.

scholarly journals Determinants of mRNA stability in Dictyostelium discoideum amoebae: differences in poly(A) tail length, ribosome loading, and mRNA size cannot account for the heterogeneity of mRNA decay rates.

1988 ◽  
Vol 8 (5) ◽  
pp. 1957-1969 ◽  
Author(s):  
R A Shapiro ◽  
D Herrick ◽  
R E Manrow ◽  
D Blinder ◽  
A Jacobson
Keyword(s):  
Steady State ◽  
Dictyostelium Discoideum ◽  
Mrna Decay ◽  
Decay Rates ◽  
Time Dependent ◽  
Translational Efficiency ◽  
Cdna Clones ◽  
Dependent Manner ◽  
Significant Difference ◽  
Kinetics Of

As an approach to understanding the structures and mechanisms which determine mRNA decay rates, we have cloned and begun to characterize cDNAs which encode mRNAs representative of the stability extremes in the poly(A)+ RNA population of Dictyostelium discoideum amoebae. The cDNA clones were identified in a screening procedure which was based on the occurrence of poly(A) shortening during mRNA aging. mRNA half-lives were determined by hybridization of poly(A)+ RNA, isolated from cells labeled in a 32PO4 pulse-chase, to dots of excess cloned DNA. Individual mRNAs decayed with unique first-order decay rates ranging from 0.9 to 9.6 h, indicating that the complex decay kinetics of total poly(A)+ RNA in D. discoideum amoebae reflect the sum of the decay rates of individual mRNAs. Using specific probes derived from these cDNA clones, we have compared the sizes, extents of ribosome loading, and poly(A) tail lengths of stable, moderately stable, and unstable mRNAs. We found (i) no correlation between mRNA size and decay rate; (ii) no significant difference in the number of ribosomes per unit length of stable versus unstable mRNAs, and (iii) a general inverse relationship between mRNA decay rates and poly(A) tail lengths. Collectively, these observations indicate that mRNA decay in D. discoideum amoebae cannot be explained in terms of random nucleolytic events. The possibility that specific 3'-structural determinants can confer mRNA instability is suggested by a comparison of the labeling and turnover kinetics of different actin mRNAs. A correlation was observed between the steady-state percentage of a given mRNA found in polysomes and its degree of instability; i.e., unstable mRNAs were more efficiently recruited into polysomes than stable mRNAs. Since stable mRNAs are, on average, "older" than unstable mRNAs, this correlation may reflect a translational role for mRNA modifications that change in a time-dependent manner. Our previous studies have demonstrated both a time-dependent shortening and a possible translational role for the 3' poly(A) tracts of mRNA. We suggest, therefore, that the observed differences in the translational efficiency of stable and unstable mRNAs may, in part, be attributable to differences in steady-state poly(A) tail lengths.

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