scholarly journals Translation elongation and mRNA stability are coupled through the ribosomal A-site

2018 ◽  
Author(s):  
Gavin Hanson ◽  
Najwa Alhusaini ◽  
Nathan Morris ◽  
Thomas Sweet ◽  
Jeff Coller
Keyword(s):  
Amino Acid ◽  
Mrna Stability ◽  
Transcript Level ◽  
Amino Acid Identity ◽  
Elongation Rate ◽  
Ribosome Profiling ◽  
Translation Elongation ◽  
Acid Identity ◽  
Optimal Codons ◽  
A Site

AbstractMessenger RNA (mRNA) degradation plays a critical role in regulating transcript levels in eukaryotic cells. Previous work by us and others has shown that codon identity exerts a powerful influence on mRNA stability. In Saccharomyces cerevisiae, studies using a handful of reporter mRNAs show that optimal codons increase translation elongation rate, which in turn increase mRNA stability. However, a direct link between elongation rate and mRNA stability has not been established across the entire yeast transcriptome. In addition, there is evidence from work in higher eukaryotes that amino acid identity influences mRNA stability, raising the question as to whether the impact of translation elongation on mRNA decay is at the level of tRNA decoding, amino acid incorporation, or some combination of each. To address these questions, we performed ribosome profiling of wildtype yeast. In good agreement with other studies, our data showed faster codon-specific elongation over optimal codons and faster transcript-level elongation correlating with transcript optimality. At both the codon-level and transcript-level, faster elongation correlated with increased mRNA stability. These findings were reinforced by showing increased translation efficiency and kinetics for a panel of 11 HIS3 reporter mRNAs of increasing codon optimality. While we did observe that elongation measured by ribosome profiling is composed of both amino acid identity and synonymous codon effects, further analyses of these data establish that A-site tRNA decoding rather than other steps of translation elongation is driving mRNA decay in yeast.

scholarly journals The Ccr4-Not complex monitors the translating ribosome for codon optimality

Science ◽  
2020 ◽  
Vol 368 (6488) ◽  
pp. eaay6912 ◽  
Author(s):  
Robert Buschauer ◽  
Yoshitaka Matsuo ◽  
Takato Sugiyama ◽  
Ying-Hsin Chen ◽  
Najwa Alhusaini ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Messenger Rna ◽  
Mrna Decay ◽  
Specific Interaction ◽  
Ribosome Profiling ◽  
Translation Elongation ◽  
Cryo Electron Microscopy ◽  
A Site ◽  
Sense Codon ◽  
Decoding Efficiency

Control of messenger RNA (mRNA) decay rate is intimately connected to translation elongation, but the spatial coordination of these events is poorly understood. The Ccr4-Not complex initiates mRNA decay through deadenylation and activation of decapping. We used a combination of cryo–electron microscopy, ribosome profiling, and mRNA stability assays to examine the recruitment of Ccr4-Not to the ribosome via specific interaction of the Not5 subunit with the ribosomal E-site in Saccharomyces cerevisiae. This interaction occurred when the ribosome lacked accommodated A-site transfer RNA, indicative of low codon optimality. Loss of the interaction resulted in the inability of the mRNA degradation machinery to sense codon optimality. Our findings elucidate a physical link between the Ccr4-Not complex and the ribosome and provide mechanistic insight into the coupling of decoding efficiency with mRNA stability.

scholarly journals Codon Usage and Amino Acid Identity Are Major Determinants of MRNA Stability in Humans

2018 ◽  
Author(s):  
Megan E. Forrest ◽  
Ashrut Narula ◽  
Thomas J. Sweet ◽  
Daniel Arango ◽  
Gavin Hanson ◽  
...  
Keyword(s):  
Amino Acid ◽  
Codon Usage ◽  
Mrna Stability ◽  
Amino Acid Identity ◽  
Acid Identity

scholarly journals The Ccr4-Not complex monitors the translating ribosome for codon optimality

2019 ◽  
Author(s):  
Robert Buschauer ◽  
Yoshitaka Matsuo ◽  
Ying-Hsin Chen ◽  
Najwa Alhusaini ◽  
Thomas Sweet ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Mrna Decay ◽  
Specific Interaction ◽  
Ribosome Profiling ◽  
Translation Elongation ◽  
Cryo Electron Microscopy ◽  
A Site ◽  
Sense Codon ◽  
Decoding Efficiency ◽  
Insight Into

Control of mRNA decay rate is intimately connected to translation elongation but the spatial coordination of these events is poorly understood. The Ccr4-Not complex initiates mRNA decay through deadenylation and activation of decapping. Using a combination of cryo-electron microscopy, ribosome profiling and mRNA stability assays we show recruitment of Ccr4-Not to the ribosome via specific interaction of the Not5 subunit with the ribosomal E-site. This interaction only occurs when the ribosome lacks accommodated A-site tRNA, indicative of low codon optimality. Loss of Not5 results in the inability of the mRNA degradation machinery to sense codon optimality. Our analysis elucidates a physical link between the Ccr4-Not complex and the ribosome providing mechanistic insight into the coupling of decoding efficiency with mRNA stability.

scholarly journals Codon usage and amino acid identity are major determinants of mRNA stability in humans

2018 ◽  
Author(s):  
Megan E. Forrest ◽  
Ashrut Narula ◽  
Thomas J Sweet ◽  
Daniel Arango ◽  
Gavin Hanson ◽  
...  
Keyword(s):  
Amino Acid ◽  
Codon Usage ◽  
Mrna Stability ◽  
Protein Sequence ◽  
Synonymous Codon ◽  
Amino Acid Identity ◽  
Mrna Degradation ◽  
Model Organisms ◽  
Mrna Levels ◽  
Acid Identity

mRNA degradation is a critical, yet poorly understood, aspect of gene expression. Previous studies demonstrate that codon content acts as a major determinant of mRNA stability in model organisms. In humans, the importance of open reading frame (ORF)-mediated regulation remains unclear. Here, we globally analyzed mRNA stability for both endogenous and human ORFeome collection mRNAs in human cells. Consistent with previous studies, we observed that synonymous codon usage impacts human mRNA decay. Unexpectedly, amino acid identity also acts as a driver of translation-dependent decay, meaning that primary protein sequence dictates overall mRNA levels and, consequently, protein abundance. Both codon usage and amino acid identity affect translational elongation rate to varying degrees in distinct organisms, with the net result being sensed by mRNA degradation machinery. In humans, interplay between ORF- and UTR-mediated control of mRNA stability may be critical to offset this fundamental relationship between protein sequence and mRNA abundance.

Functional and Structural Characterization of Acquired Pan-Aminoglycoside Resistance 16S rRNA Methyltransferase NpmB1

2021 ◽  
Author(s):  
Akito Kawai ◽  
Masahiro Suzuki ◽  
Kentaro Tsukamoto ◽  
Yusuke Minato ◽  
Yohei Doi
Keyword(s):  
Amino Acid ◽  
16S Rrna ◽  
Amino Acid Identity ◽  
Single Amino Acid ◽  
Aminoglycoside Resistance ◽  
E Coli ◽  
The United Kingdom ◽  
Amino Acid Variant ◽  
A Site

Post-translational methylation of the A site of 16S rRNA at position A1408 leads to pan-aminoglycoside resistance encompassing both 4,5- and 4,6-disubstituted 2-deoxystreptamine (DOS) aminoglycosides. To date, NpmA is the only acquired enzyme with such function. Here, we present function and structure of NpmB1 whose sequence was identified in Escherichia coli genomes registered from the United Kingdom. NpmB1 possesses 40% amino acid identity with NpmA1 and confers resistance to all clinically relevant aminoglycosides including 4,5-DOS agents. Phylogenetic analysis of NpmB1 and NpmB2, its single amino acid variant, revealed that the encoding gene was likely acquired by E. coli from a soil bacterium. The structure of NpmB1 suggests that it requires a structural change of the β6/7 linker in order to bind to 16S rRNA. These findings establish NpmB1 and NpmB2 as the second group of acquired pan-aminoglycoside resistance 16S rRNA methyltransferases.

scholarly journals A50 Whole-genome sequencing of African swine fever isolates from Sardinia

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
C Torresi ◽  
F Granberg ◽  
L Bertolotti ◽  
A Oggiano ◽  
B Colitti ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sequence Data ◽  
Temporal Distribution ◽  
African Swine Fever ◽  
Amino Acid Identity ◽  
Genotype I ◽  
Acid Identity ◽  
Wide Range ◽  
Intergenic Sequences ◽  
Genes Encoding

Abstract In order to assess the molecular epidemiology of African swine fever (ASF) in Sardinia, we analyzed a wide range of isolates from wild and domestic pigs over a 31-year period (1978–2009) by genotyping sequence data from the genes encoding the p54 and the p72 proteins and the CVR. On this basis, the analysis of the B602L gene revealed a minor difference, placing the Sardinian isolates into two clusters according to their temporal distribution. As an extension of this study, in order to achieve a higher level of discrimination, three further variable genome regions, namely p30, CD2v, and I73R/I329L, of a large number of isolates collected from outbreaks in the years 2002–14 have been investigated. Sequence analysis of the CD2v region revealed a temporal subdivision of the viruses into two subgroups. These data, together with those from the B602L gene analysis, demonstrated that the viruses circulating in Sardinia belong to p72/genotype I, but since 1990 have undergone minor genetic variations in respect to its ancestor, thus making it impossible to trace isolates, enabling a more accurate assessment of the origin of outbreaks, and extending knowledge of virus evolution. To solve this problem, we have sequenced and annotated the complete genome of nine ASF isolates collected in Sardinia between 1978 and 2012. This was achieved using sequence data determined by next-generation sequencing. The results showed a very high identity with range of nucleotide similarity among isolates of 99.5 per cent to 99.9 per cent. The ASF virus (ASFV) genomes were composed of terminal inverted repeats and conserved and non-conserved ORFs. Among the conserved ORFs, B385R, H339R, and O61R-p12 showed 100 per cent amino acid identity. The same was true for the hypervariable ORFs, with regard to X69R, DP96R, DP60R, EP153R, B407L, I10L, and L60L genes. The EP402R and B602L genes showed, as expected, an amino acid identity range of 98.5 per cent to 100 per cent and 91 per cent to 100 per cent, respectively. In addition, all of the isolates displayed variable intergenic sequences. As a whole, the results from our studies confirmed a remarkable genetic stability of the ASFV/p72 genotype I viruses circulating in Sardinia.

Characterization and Induction of Two Cytochrome P450 Genes, CYP6AE28 and CYP6AE30, in Cnaphalocrocis medinalis: Possible Involvement in Metabolism of Rice Allelochemicals

2010 ◽  
Vol 65 (11-12) ◽  
pp. 719-725 ◽  
Author(s):  
Xiaoli Liu ◽  
Jun Chen ◽  
Zhifan Yang
Keyword(s):  
Amino Acid ◽  
Rice Variety ◽  
Amino Acid Identity ◽  
Cnaphalocrocis Medinalis ◽  
Amino Acid Residues ◽  
Acid Identity ◽  
Rice Leaf Folder ◽  
Cytochrome P450 Genes ◽  
Molecular Masses ◽  
Lepidoptera Pyralidae

Two cDNAs specific for P450 genes, CYP6AE28 and CYP6AE30, have been isolated from the rice leaf folder Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae). Both cDNApredicted proteins have 504 amino acid residues in length, but with molecular masses of 60177 Dalton for CYP6AE28 and 60020 Dalton for CYP6AE30, and theoretical pI values of 8.49 for CYP6AE28 and 8.56 for CYP6AE30, respectively. Both putative proteins contain the conserved structural and functional domains characteristic of all CYP6 members. CYP6AE28 and CYP6AE30 show 52% amino acid identity to each other; both of them have 49 - 56% identities with CYP6AE1, Cyp6ae12, and CYP6AE14. Phylogenetic analysis showed that the two P450s are grouped in the lineage containing some of the CYP6AE members, CYP6B P450s and CYP321A1. The transcripts of CYP6AE28 and CYP6AE30 were found to be induced in response to TKM-6, a rice variety with high resistance to C. medinalis. The results suggest that the two P450s may play important roles in adaptation to the host plant rice. This is the first report of P450 genes cloned in C. medinalis

scholarly journals Inferring efficiency of translation initiation and elongation from ribosome profiling

2020 ◽  
Vol 48 (17) ◽  
pp. 9478-9490
Author(s):  
Juraj Szavits-Nossan ◽  
Luca Ciandrini
Keyword(s):  
Protein Synthesis ◽  
Mathematical Modelling ◽  
Translation Initiation ◽  
Mrna Translation ◽  
Elongation Rate ◽  
Ribosome Profiling ◽  
Translation Elongation ◽  
Recent Advances ◽  
Two Stages

Abstract One of the main goals of ribosome profiling is to quantify the rate of protein synthesis at the level of translation. Here, we develop a method for inferring translation elongation kinetics from ribosome profiling data using recent advances in mathematical modelling of mRNA translation. Our method distinguishes between the elongation rate intrinsic to the ribosome’s stepping cycle and the actual elongation rate that takes into account ribosome interference. This distinction allows us to quantify the extent of ribosomal collisions along the transcript and identify individual codons where ribosomal collisions are likely. When examining ribosome profiling in yeast, we observe that translation initiation and elongation are close to their optima and traffic is minimized at the beginning of the transcript to favour ribosome recruitment. However, we find many individual sites of congestion along the mRNAs where the probability of ribosome interference can reach $50\%$. Our work provides new measures of translation initiation and elongation efficiencies, emphasizing the importance of rating these two stages of translation separately.

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