scholarly journals Extensive translation of small ORFs revealed by polysomal ribo-Seq

2014 ◽  
Author(s):  
Julie L Aspden ◽  
Ying Chen Eyre-Walker ◽  
Rose J. Phillips ◽  
Michele Brocard ◽  
Unum Amin ◽  
...  

Thousands of small Open Reading Frames (smORFs) encoding small peptides of fewer than 100 amino acids exist in our genomes. Examples of functional smORFs have been characterised in a few species but the actual number of translated smORFs, and their molecular, functional and evolutionary features are not known. Here we present a genome-wide assessment of smORF translation by ribosomal profiling of polysomal fractions. This ‘polysomal ribo-Seq’ suggests that smORFs are translated at the same level and in the same relative numbers (80%) as normal proteins. The smORF peptides appear widely conserved, show activity in cells, and display a putative amino acid signature. These findings reinforce the idea that smORFs are an abundant and fundamental genome component, displaying features usually attributed to canonical proteins, including high translation levels, biological function, amino acid sequence specificity and cross-species conservation.

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Julie L Aspden ◽  
Ying Chen Eyre-Walker ◽  
Rose J Phillips ◽  
Unum Amin ◽  
Muhammad Ali S Mumtaz ◽  
...  

Thousands of small Open Reading Frames (smORFs) with the potential to encode small peptides of fewer than 100 amino acids exist in our genomes. However, the number of smORFs actually translated, and their molecular and functional roles are still unclear. In this study, we present a genome-wide assessment of smORF translation by ribosomal profiling of polysomal fractions in Drosophila. We detect two types of smORFs bound by multiple ribosomes and thus undergoing productive translation. The ‘longer’ smORFs of around 80 amino acids resemble canonical proteins in translational metrics and conservation, and display a propensity to contain transmembrane motifs. The ‘dwarf’ smORFs are in general shorter (around 20 amino-acid long), are mostly found in 5′-UTRs and non-coding RNAs, are less well conserved, and have no bioinformatic indicators of peptide function. Our findings indicate that thousands of smORFs are translated in metazoan genomes, reinforcing the idea that smORFs are an abundant and fundamental genome component.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yan Liang ◽  
Wanchao Zhu ◽  
Sijia Chen ◽  
Jia Qian ◽  
Lin Li

Small peptides (sPeptides), <100 amino acids (aa) long, are encoded by small open reading frames (sORFs) often found in the 5′ and 3′ untranslated regions (or other parts) of mRNAs, in long non-coding RNAs, or transcripts from introns and intergenic regions; various sPeptides play important roles in multiple biological processes. In this study, we conducted a comprehensive study of maize (Zea mays) sPeptides using mRNA sequencing, ribosome profiling (Ribo-seq), and mass spectrometry (MS) on six tissues (each with at least two replicates). To identify maize sORFs and sPeptides from these data, we set up a robust bioinformatics pipeline and performed a genome-wide scan. This scan uncovered 9,388 sORFs encoding peptides of 2–100 aa. These sORFs showed distinct genomic features, such as different Kozak region sequences, higher specificity of translation, and high translational efficiency, compared with the canonical protein-coding genes. Furthermore, the MS data verified 2,695 sPeptides. These sPeptides perfectly discriminated all the tissues and were highly associated with their parental genes. Interestingly, the parental genes of sPeptides were significantly enriched in multiple functional gene ontology terms related to abiotic stress and development, suggesting the potential roles of sPeptides in the regulation of their parental genes. Overall, this study lays out the guidelines for genome-wide scans of sORFs and sPeptides in plants by integrating Ribo-seq and MS data and provides a more comprehensive resource of functional sPeptides in maize and gives a new perspective on the complex biological systems of plants.


2002 ◽  
Vol 184 (17) ◽  
pp. 4881-4890 ◽  
Author(s):  
Robert A. Britton ◽  
Patrick Eichenberger ◽  
Jose Eduardo Gonzalez-Pastor ◽  
Paul Fawcett ◽  
Rita Monson ◽  
...  

ABSTRACT Sigma-H is an alternative RNA polymerase sigma factor that directs the transcription of many genes that function at the transition from exponential growth to stationary phase in Bacillus subtilis. Twenty-three promoters, which drive transcription of 33 genes, are known to be recognized by sigma-H-containing RNA polymerase. To identify additional genes under the control of sigma-H on a genome-wide basis, we carried out transcriptional profiling experiments using a DNA microarray containing >99% of the annotated B. subtilis open reading frames. In addition, we used a bioinformatics-based approach aimed at the identification of promoters recognized by RNA polymerase containing sigma-H. This combination of approaches was successful in confirming most of the previously described sigma-H-controlled genes. In addition, we identified 26 putative promoters that drive expression of 54 genes not previously known to be under the direct control of sigma-H. Based on the known or inferred function of most of these genes, we conclude that, in addition to its previously known roles in sporulation and competence, sigma-H controls genes involved in many physiological processes associated with the transition to stationary phase, including cytochrome biogenesis, generation of potential nutrient sources, transport, and cell wall metabolism.


2020 ◽  
Author(s):  
Chao Yan ◽  
Yupeng Wang ◽  
Tao Lyu ◽  
Zhikang Hu ◽  
Ning Ye ◽  
...  

Abstract Background: Genome-wide change of polyadenylation (polyA) sites (also known as alternative polyadenylation, APA) is emerging as an important strategy of gene regulation in response to stress in plants. But little is known in woody perennials that are persistently dealing with multiple abiotic stresses. Results: Here, we performed a genome-wide profiling of polyadenylation sites under heat and cold treatments in Populus trichocarpa. Through a comprehensive analysis of polyA tail sequences, we identified 25,919 polyA-site clusters (PACs), and revealed 3429 and 3139 genes shifted polyA sites under heat and cold stresses respectively. We found that a small proportion of genes possessed APA that affected the open reading frames; and some shifts were commonly identified. Functional analysis of genes displaying shifted polyA tails suggested that pathways related to RNA metabolism were linked to regulate the APA events under both heat and cold stresses. Interestingly, we found that the heat stress induced a significantly more antisense PACs comparing to cold and control conditions. Furthermore, we showed that a unique cis-element (AAAAAA) was predominately enriched downstream of PACs in P. trichocarpa genes; and this sequence signal was only absent in shifted PACs under the heat condition, indicating a distinct APA mechanism responsive to heat tolerance. Conclusions: This work provides a comprehensive picture of global polyadenylation patterns in response to temperatures stresses in trees. We show that the frequent change of polyA tail is a potential mechanism of gene regulation responsive to stress, which are associated with distinctive sequence signatures.


2021 ◽  
Author(s):  
Taeko Shibaya ◽  
Chika Kuroda ◽  
Hisano Tsuruoka ◽  
Chiharu Minami ◽  
Akiko Obara ◽  
...  

Abstract Carrot is a major source of provitamin A in a human diet. Two of the most important traits for carrot breeding are carotenoid contents and root color. To examine genomic regions related to these traits and develop DNA markers for carrot breeding, we performed a genome-wide association study (GWAS) using genome-wide single-nucleotide polymorphisms (SNPs) in two F2 populations, both derived from crosses of orange root carrots bred by a Japanese seed company. The GWAS revealed 21 significant associations, and the physical position of some associations suggested two possible candidate genes. An Orange (Or) gene was a possible candidate for visual color evaluation and the α- and β-carotene contents. Sanger sequencing detected a new allele of Or with an SNP which caused a non-synonymous amino acid substitution. Genotypes of this SNP corresponded to the visual evaluation of root color in another breeding line. A chromoplast-specific lycopene β-cyclase (CYC-B) gene was a possible candidate for the β/α carotene ratio. On CYC-B, five amino acid substitutions were detected between parental plants of the F2 population. The detected associations and SNPs on the possible candidate genes will contribute to carrot breeding and the understanding of carotenoid biosynthesis and accumulation in orange carrots.


2021 ◽  
Vol 118 (11) ◽  
pp. e2004199118
Author(s):  
Marina Penova ◽  
Shuji Kawaguchi ◽  
Jun-ichirou Yasunaga ◽  
Takahisa Kawaguchi ◽  
Tomoo Sato ◽  
...  

HTLV-1–associated myelopathy (HAM/TSP) is a chronic and progressive inflammatory disease of the central nervous system. The aim of our study was to identify genetic determinants related to the onset of HAM/TSP in the Japanese population. We conducted a genome-wide association study comprising 753 HAM/TSP patients and 899 asymptomatic HTLV-1 carriers. We also performed comprehensive genotyping of HLA-A, -B, -C, -DPB1, -DQB1, and -DRB1 genes using next-generation sequencing technology for 651 HAM/TSP patients and 804 carriers. A strong association was observed in HLA class I (P = 1.54 × 10−9) and class II (P = 1.21 × 10−8) loci with HAM/TSP. Association analysis using HLA genotyping results showed that HLA-C*07:02 (P = 2.61 × 10−5), HLA-B*07:02 (P = 4.97 × 10−10), HLA-DRB1*01:01 (P = 1.15 × 10−9) and HLA-DQB1*05:01 (P = 2.30 × 10−9) were associated with disease risk, while HLA-B*40:06 (P = 3.03 × 10−5), HLA-DRB1*15:01 (P = 1.06 × 10−5) and HLA-DQB1*06:02 (P = 1.78 × 10−6) worked protectively. Logistic regression analysis identified amino acid position 7 in the G-BETA domain of HLA-DRB1 as strongly associated with HAM/TSP (P = 9.52 × 10−10); individuals homozygous for leucine had an associated increased risk of HAM/TSP (odds ratio, 9.57), and proline was protective (odds ratio, 0.65). Both associations were independent of the known risk associated with proviral load. DRB1-GB-7-Leu was not significantly associated with proviral load. We have identified DRB1-GB-7-Leu as a genetic risk factor for HAM/TSP development independent of proviral load. This suggests that the amino acid residue may serve as a specific marker to identify the risk of HAM/TSP even without knowledge of proviral load. In light of its allele frequency worldwide, this biomarker will likely prove useful in HTLV-1 endemic areas across the globe.


2016 ◽  
Vol 113 (46) ◽  
pp. 13109-13113 ◽  
Author(s):  
Igor B. Rogozin ◽  
Frida Belinky ◽  
Vladimir Pavlenko ◽  
Svetlana A. Shabalina ◽  
David M. Kristensen ◽  
...  

Serine is the only amino acid that is encoded by two disjoint codon sets so that a tandem substitution of two nucleotides is required to switch between the two sets. Previously published evidence suggests that, for the most evolutionarily conserved serines, the codon set switch occurs by simultaneous substitution of two nucleotides. Here we report a genome-wide reconstruction of the evolution of serine codons in triplets of closely related species from diverse prokaryotes and eukaryotes. The results indicate that the great majority of codon set switches proceed by two consecutive nucleotide substitutions, via a threonine or cysteine intermediate, and are driven by selection. These findings imply a strong pressure of purifying selection in protein evolution, which in the case of serine codon set switches occurs via an initial deleterious substitution quickly followed by a second, compensatory substitution. The result is frequent reversal of amino acid replacements and, at short evolutionary distances, pervasive homoplasy.


2020 ◽  
Author(s):  
Zheng Liu ◽  
Xiao-Xia Ge ◽  
Xiao-Meng Wu ◽  
Qiang Xu ◽  
Ross G. Atkinson ◽  
...  

Abstract Background: In citrus, genetic improvement via biotechnology is hindered by the obstacle of in vitro regeneration via somatic embryogenesis (SE). Although a few B3 transcription factors are reported to regulate embryogenesis, little is known about the B3 superfamily in citrus, and which members might be involved in SE.Results: Genome-wide sequence analysis identified 72 (CsB3) and 69 (CgB3) putative B3 superfamily members in the genomes of sweet orange (Citrus sinensis, polyembryonic) and pummelo (C. grandis, monoembryonic), respectively. Genome duplication analysis indicated that segmental and tandem duplication events contributed to the expansion of the B3 superfamily in citrus, and that the B3 superfamily evolved under the effect of purifying selection. Phylogenetic relationships were well supported by conserved gene structure and motifs outside the B3 domain, which allowed possible functions to be inferred by comparison with homologous genes from Arabidopsis. Expression analysis identified 23 B3 superfamily members that were expressed during SE in citrus and 17 that may play functional roles at late SE stages. Eight B3 genes were identified that were specific to the genome of polyembryonic sweet orange compared to monoembryonic pummelo. Of these eight B3 genes, CsARF19 was found to be specifically expressed at higher levels in embryogenic callus (EC), implying its possible involvement in EC initiation. Conclusions: This study provides a genome-wide analysis of the citrus B3 superfamily, including its genome organization, evolutionary features and expression profiles, and identifies specific family members that may be associated with SE.


2019 ◽  
Author(s):  
Zheng Liu ◽  
Xiao-Xia Ge ◽  
Xiao-Meng Wu ◽  
Wen-Wu Guo

Abstract Background In citrus, genetic improvement via biotechnology is hindered by the obstacle of in vitro regeneration via somatic embryogenesis (SE). Although a few of B3 transcription factors are reported to regulate embryogenesis, little is known about the possible roles of B3 superfamily during SE especially in citrus. Results In this study, a total of 72 (CsB3) and 69 (CgB3) putative B3 superfamily members were identified in the sweet orange (Citrus sinensis) and pummelo (C. grandis) genomes, respectively, each comprised four gene families and 14 phylogenetic classes. The B3 genes were unevenly distributed over citrus chromosomes and other non-anchored scaffolds. Genome duplication analysis indicated that the segmental and tandem duplication events have significantly contributed to the expansion of the citrus B3 superfamily. The evolutionary relationships among the B3 family members and their putative functions were deduced based on the results of phylogenetic analysis. Furthermore, transcriptomic analysis showed that citrus B3 genes have differential expression levels in various tissues, suggesting distinct biological roles of different members. Expression analysis revealed that the B3 superfamily members showed four types of expression profiles during SE in citrus and may play functional roles during SE, especially at late SE stages. Of them, CsARF19 is specifically expressed in sweet orange and at markedly higher levels in the embryogenic callus (EC), implying its possible involvement in EC initiation. Conclusions This study provides a genome-wide analysis of citrus B3 superfamily, including its genome organization, evolutionary features and expression profiles, which contributes to a better understanding of the B3 genes in citrus and their association with SE.


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