scholarly journals Identification and in Silico Characterization of Novel and Conserved MicroRNAs in Methyl Jasmonate-Stimulated Scots Pine (Pinus sylvestris L.) Needles

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 384
Author(s):  
Baiba Krivmane ◽  
Ilze Šņepste ◽  
Vilnis Šķipars ◽  
Igor Yakovlev ◽  
Carl Gunnar Fossdal ◽  
...  
Keyword(s):  
Methyl Jasmonate ◽  
Scots Pine ◽  
Target Genes ◽  
Regulation Of Gene Expression ◽  
Stem Loop ◽  
Protein Coding ◽  
Stem Loop Structure ◽  
In Silico Characterization ◽  
Potential Precursor

MicroRNAs (miRNAs) are non-protein coding RNAs of ~20–24 nucleotides in length that play an important role in many biological and metabolic processes, including the regulation of gene expression, plant growth and developmental processes, as well as responses to stress and pathogens. The aim of this study was to identify and characterize novel and conserved microRNAs expressed in methyl jasmonate-treated Scots pine needles. In addition, potential precursor sequences and target genes of the identified miRNAs were determined by alignment to the Pinus unigene set. Potential precursor sequences were identified using the miRAtool, conserved miRNA precursors were also tested for the ability to form the required stem-loop structure, and the minimal folding free energy indexes were calculated. By comparison with miRBase, 4975 annotated sequences were identified and assigned to 173 miRNA groups, belonging to a total of 60 conserved miRNA families. A total of 1029 potential novel miRNAs, grouped into 34 families were found, and 46 predicted precursor sequences were identified. A total of 136 potential target genes targeted by 28 families were identified. The majority of previously reported highly conserved plant miRNAs were identified in this study, as well as some conserved miRNAs previously reported to be monocot specific. No conserved dicot-specific miRNAs were identified. A number of potential gymnosperm or conifer specific miRNAs were found, shared among a range of conifer species.

scholarly journals Identification and characterization of a sequence motif involved in nonsense-mediated mRNA decay.

1995 ◽  
Vol 15 (4) ◽  
pp. 2231-2244 ◽  
Author(s):  
S Zhang ◽  
M J Ruiz-Echevarria ◽  
Y Quan ◽  
S W Peltz
Keyword(s):  
Mrna Decay ◽  
Sequence Motif ◽  
Nonsense Mutations ◽  
Stem Loop ◽  
Cis Acting ◽  
Stem Loop Structure ◽  
Nonsense Codon ◽  
Nonsense Mediated Mrna Decay

In both prokaryotes and eukaryotes, nonsense mutations in a gene can enhance the decay rate or reduce the abundance of the mRNA transcribed from that gene, and we call this process nonsense-mediated mRNA decay. We have been investigating the cis-acting sequences involved in this decay pathway. Previous experiments have demonstrated that, in addition to a nonsense codon, specific sequences 3' of a nonsense mutation, which have been defined as downstream elements, are required for mRNA destabilization. The results presented here identify a sequence motif (TGYYGATGYYYYY, where Y stands for either T or C) that can predict regions in genes that, when positioned 3' of a nonsense codon, promote rapid decay of its mRNA. Sequences harboring two copies of the motif from five regions in the PGK1, ADE3, and HIS4 genes were able to function as downstream elements. In addition, four copies of this motif can function as an independent downstream element. The sequences flanking the motif played a more significant role in modulating its activity when fewer copies of the sequence motif were present. Our results indicate the sequences 5' of the motif can modulate its activity by maintaining a certain distance between the sequence motif and the termination codon. We also suggest that the sequences 3' of the motif modulate the activity of the downstream element by forming RNA secondary structures. Consistent with this view, a stem-loop structure positioned 3' of the sequence motif can enhance the activity of the downstream element. This sequence motif is one of the few elements that have been identified that can predict regions in genes that can be involved in mRNA turnover. The role of these sequences in mRNA decay is discussed.

sRNA STnc150 is involved in virulence regulation of Salmonella Typhimurium by targeting fimA mRNA

2021 ◽  
Vol 368 (18) ◽  
Author(s):  
Jing Li ◽  
Na Li ◽  
Chengcheng Ning ◽  
Yun Guo ◽  
Chunhui Ji ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Target Genes ◽  
Reporter System ◽  
Stem Loop ◽  
Viral Loads ◽  
Virulence Regulation ◽  
Stem Loop Structure ◽  
Complementary Strain

ABSTRACT Small RNAs (sRNAs) are essential virulent regulators in Salmonella typhimurium (STM). To explore the role of sRNA STnc150 in regulating STM virulence, we constructed a STnc150 deletion strain (ΔSTnc150) and its complementary strain (ΔSTnc150/C). Then, we compared their characteristics to their original parent strain experimentally, identified the target genes of STnc150 and determined the expression levels of target genes. The results showed that the ΔSTnc150 strain exhibited delayed biofilm formation, enhanced adhesion to macrophages, significantly reduced LD50, increased liver and spleen viral loads and more vital pathological damaging ability than its parent and complementary strains. Further, bioinformatics combined with the bacterial dual plasmid reporter system confirmed that the bases 72–88 of STnc150 locating at the secondary stem-loop structure of the STnc150 are complementary with the bases 1–19 in the 5′-terminal of fimA mRNA of the type 1 fimbriae subunit. Western blot analysis showed that fimA protein level was increased in STnc150 strain compared with its parent and complementary strains. Together, this study suggested that STnc150 can down-regulate STM fimA expression at the translation level, which provided insights into the regulatory mechanisms of sRNAs in virulence of STM.

scholarly journals Antigene-block strategy: Effective regulation of gene expression by 2′,4′-BNA-modified TFOs with an additional stem-loop structure

2005 ◽  
Vol 49 (1) ◽  
pp. 335-336 ◽  
Author(s):  
Naoto Tsuda ◽  
Ayumi Matsumoto ◽  
Aya Ito ◽  
Tomomi Uneda ◽  
Atsuhiro Tanabe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Regulation Of Gene Expression ◽  
Loop Structure ◽  
Stem Loop ◽  
Stem Loop Structure

Molecular detection and in silico characterization of cold shock protein coding gene (cspA) from cold adaptive Pseudomonas koreensis

2019 ◽  
Vol 28 (4) ◽  
pp. 405-413 ◽  
Author(s):  
Srikant Awasthi ◽  
Anjney Sharma ◽  
Pragya Saxena ◽  
Jagriti Yadav ◽  
K. Pandiyan ◽  
...  
Keyword(s):  
In Silico ◽  
Molecular Detection ◽  
Cold Shock ◽  
Cold Shock Protein ◽  
Protein Coding ◽  
In Silico Characterization

scholarly journals The roles of rice microRNAs in rice-Magnaporthe oryzae interaction

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Yan Li ◽  
John Martin Jerome Jeyakumar ◽  
Qin Feng ◽  
Zhi-Xue Zhao ◽  
Jing Fan ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Magnaporthe Oryzae ◽  
Functional Characterization ◽  
Mature Mirnas ◽  
Transcriptional Gene Silencing ◽  
Rnase Iii ◽  
Stem Loop ◽  
Mirna Genes ◽  
Stem Loop Structure

AbstractMicroRNAs (miRNAs) are a class of small (20–24 nucleotides (nt) long) non-coding RNAs. One mature miRNA can be transcribed from one or more gene loci known as miRNA genes (MIRs). The transcript of a MIR forms a stem-loop structure that is processed into a 20–24-nt miRNA-5p/−3p duplex by RNase III family endoribonucleases such as Dicer-like1 (DCL1). In turn, the overhang ends of the duplex are methylated by HUA ENHANCER 1 (HEN1), generating stabilized mature miRNAs. The mature miRNAs are loaded onto ARGONAUTE (AGO) proteins, forming a miRNA-induced gene silencing complex (miRISC). Then, the miRISC binds to target sites with sequences complementary to the miRNAs, leading to either cleavage or translational inhibition of the target mRNAs, or methylation of the target sequences, resulting in post-transcriptional and transcriptional gene silencing, respectively. In the past decade, more than 700 miRNAs have been identified in rice, a subset of which have been found to be responsive to the rice blast fungus, Magnaporthe oryzae, or its elicitors. Moreover, members of 10 miRNA families have been found to positively or negatively regulate rice defense against M. oryzae, namely miR160, miR164, miR166, miR167, miR169, miR319, miR396, miR398, miR444 and miR7695. This review summarizes the identification and functional characterization of the miRNAs, which respond to M. oryzae or its elicitors and describes the current understanding of the complicated but well-organized network in the context of rice-M. oryzae interaction.

scholarly journals SAFB2 enables the processing of suboptimal stem-loop structures in clustered primary miRNA transcripts

2019 ◽  
Author(s):  
Katharina Hutter ◽  
Michael Lohmüller ◽  
Almina Jukic ◽  
Felix Eichin ◽  
Seymen Avci ◽  
...  
Keyword(s):  
Noncoding Rnas ◽  
General Mechanism ◽  
List Type ◽  
Loop Structure ◽  
Stem Loop ◽  
Protein Coding ◽  
Mirna Processing ◽  
Small Noncoding Rnas ◽  
Stem Loop Structure ◽  
Attachment Factor

SummaryMicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally silence most protein-coding genes in mammals. They are generated from primary transcripts containing single or multiple clustered stem-loop structures that are thought to be recognized and cleaved by the DGCR8/DROSHA Microprocessor complex as independent units. Contrasting this view, we here report an unexpected mode of processing of a bicistronic cluster of the miR-15 family, miR-15a-16-1. We find that the primary miR-15a stem-loop is a poor Microprocessor substrate and is consequently not processed on its own, but that the presence of the neighboring primary miR-16-1 stem-loop on the same transcript can compensate for this deficiency in cis. Using a CRISPR/Cas9 screen, we identify SAFB2 (scaffold attachment factor B2) as an essential co-factor in this miR-16-1-assisted pri-miR-15 cleavage, and describe SAFB2 as a novel accessory protein of DROSHA. Notably, SAFB2-mediated cluster assistance expands to other clustered pri-miRNAs including miR-15b, miR-92a and miR-181b, indicating a general mechanism. Together, our study reveals an unrecognized function of SAFB2 in miRNA processing and suggests a scenario in which SAFB2 enables the binding and processing of suboptimal DGCR8/DROSHA substrates in clustered primary miRNA transcripts.Highlightsthe primary miR-15a stem-loop structure per se is a poor Microprocessor substratecleavage of pri-miR-15a requires the processing of an additional miRNA stem-loop on the same RNAsequential pri-miRNA processing or “cluster assistance” is mediated by SAFB proteinsSAFB2 associates with the Microprocessor

scholarly journals Cloning and Characterization of the Lactococcal Plasmid-Encoded Type II Restriction/Modification System, LlaDII

1998 ◽  
Vol 64 (7) ◽  
pp. 2424-2431 ◽  
Author(s):  
Annette Madsen ◽  
Jytte Josephsen
Keyword(s):  
Shuttle Vector ◽  
Open Reading Frames ◽  
Stem Loop ◽  
Modification System ◽  
Restriction Modification System ◽  
Stem Loop Structure ◽  
Methylase Gene ◽  
Sequences Alignment ◽  
Restriction Modification

ABSTRACT The LlaDII restriction/modification (R/M) system was found on the naturally occurring 8.9-kb plasmid pHW393 inLactococcus lactis subsp. cremoris W39. A 2.4-kb PstI-EcoRI fragment inserted into theEscherichia coli-L. lactis shuttle vector pCI3340 conferred to L. lactis LM2301 and L. lactis SMQ86 resistance against representatives of the three most common lactococcal phage species: 936, P335, and c2. The LlaDII endonuclease was partially purified and found to recognize and cleave the sequence 5′-GC↓NGC-3′, where the arrow indicates the cleavage site. It is thus an isoschizomer of the commercially available restriction endonuclease Fnu4HI. Sequencing of the 2.4-kbPstI-EcoRI fragment revealed two open reading frames arranged tandemly and separated by a 105-bp intergenic region. The endonuclease gene of 543 bp preceded the methylase gene of 954 bp. The deduced amino acid sequence of the LlaDII R/M system showed high homology to that of its only sequenced isoschizomer,Bsp6I from Bacillus sp. strain RFL6, with 41% identity between the endonucleases and 60% identity between the methylases. The genetic organizations of the LlaDII andBsp6I R/M systems are identical. Both methylases have two recognition sites (5′-GCGGC-3′ and 5′-GCCGC-3′) forming a putative stem-loop structure spanning part of the presumed −35 sequence and part of the intervening region between the −35 and −10 sequences. Alignment of the LlaDII andBsp6I methylases with other m5C methylases showed that the protein primary structures possessed the same organization.

Identification and characterization of microRNAs and their target genes from Nile tilapia (Oreochromis niloticus)

2016 ◽  
Vol 71 (7-8) ◽  
pp. 215-223 ◽  
Author(s):  
Yong Huang ◽  
Xiu Ying Ma ◽  
You Bing Yang ◽  
Hong Tao Ren ◽  
Xi Hong Sun ◽  
...  
Keyword(s):  
Stress Responses ◽  
Nile Tilapia ◽  
Target Genes ◽  
Expressed Sequence Tag ◽  
Mrna Levels ◽  
Stem Loop ◽  
Mirna Genes ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Survey Sequence

Abstract MicroRNAs (miRNAs) are a class of small single-stranded, endogenous 21–22 nt non-coding RNAs that regulate their target mRNA levels by causing either inactivation or degradation of the mRNAs. In recent years, miRNA genes have been identified from mammals, insects, worms, plants, and viruses. In this research, bioinformatics approaches were used to predict potential miRNAs and their targets in Nile tilapia from the expressed sequence tag (EST) and genomic survey sequence (GSS) database, respectively, based on the conservation of miRNAs in many animal species. A total of 19 potential miRNAs were detected following a range of strict filtering criteria. To test the validity of the bioinformatics method, seven predicted Nile tilapia miRNA genes were selected for further biological validation, and their mature miRNA transcripts were successfully detected by stem–loop RT-PCR experiments. Using these potential miRNAs, we found 56 potential targets in this species. Most of the target mRNAs appear to be involved in development, metabolism, signal transduction, transcription regulation and stress responses. Overall, our findings will provide an important foundation for further research on miRNAs function in the Nile tilapia.

scholarly journals Characterization of the Complete Mitochondrial Genome of Leucoma salicis (Lepidoptera: Lymantriidae) and Comparison with Other Lepidopteran Insects

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yu-Xuan Sun ◽  
Lei Wang ◽  
Guo-Qing Wei ◽  
Cen Qian ◽  
Li-Shang Dai ◽  
...  
Keyword(s):  
Mitochondrial Genome ◽  
Synonymous Codon ◽  
Complete Mitochondrial Genome ◽  
Synonymous Codon Usage ◽  
Trna Genes ◽  
Stem Loop ◽  
Protein Coding ◽  
Distinctive Features ◽  
Protein Coding Genes ◽  
Stem Loop Structure

Abstract The complete mitochondrial genome (mitogenome) of Leucoma salicis (Lepidoptera: Lymantriidae) was sequenced and annotated. It is a circular molecule of 15,334 bp, containing the 37 genes usually present in insect mitogenomes. All protein-coding genes (PCGs) are initiated by ATN codons, other than cox1, which is initiated by CGA. Three of the 13 PCGs had an incomplete termination codon, T or TA, while the others terminated with TAA. The relative synonymous codon usage of the 13 protein-coding genes (PCGs) was consistent with those of published lepidopteran sequences. All tRNA genes had typical clover-leaf secondary structures, except for the tRNASer(AGN), in which the dihydrouridine (DHU) arm could not form a stable stem-loop structure. The A + T-rich region of 325 bp had several distinctive features, including the motif ‘ATAGA’ followed by an 18 bp poly-T stretch, a microsatellite-like (AT)7 element, and an 11-bp poly-A present immediately upstream of tRNAMet. Relationships among 32 insect species were determined using Maximum Likelihood (ML), Neighbor Joining (NJ) and Bayesian Inference (BI) phylogenetic methods. These analyses confirm that L. salicis belongs to the Lymantriidae; and that Lymantriidae is a member of Noctuoidea, and is a sister taxon to Erebidae, Nolidae and Noctuidae, most closely related to Erebidae.

scholarly journals Genome-Wide Identification and Characterization of Fusarium circinatum-Responsive lncRNAs in Pinus radiata

2021 ◽  
Author(s):  
Cristina Zamora-Ballesteros ◽  
Jorge Martin-Garcia ◽  
Aroa Suarez-Vega ◽  
Julio Diez
Keyword(s):  
Cell Wall ◽  
Pinus Radiata ◽  
Target Genes ◽  
Early Stage ◽  
Gc Content ◽  
Fusarium Circinatum ◽  
Protein Coding ◽  
Biotic Stresses ◽  
Non Coding Rnas

One of the most promising strategies of Pine Pitch Canker (PPC) management is the use of reproductive plant material resistant to the disease. Understanding the complexity of plant transcriptome that underlies the defence to the causal agent Fusarium circinatum, would greatly facilitate the development of an accurate breeding program. Long non-coding RNAs (lncRNAs) are emerging as important transcriptional regulators under biotic stresses in plants. However, to date, characterization of lncRNAs in conifer trees has not been reported. In this study, transcriptomic identification of lncRNAs was carried out using strand-specific paired-end RNA sequencing, from Pinus radiata samples inoculated with F. circinatum at an early stage of infection. Overall, 13,312 lncRNAs were predicted through a bioinformatics approach, including long intergenic non-coding RNAs (92.3%), antisense lncRNAs (3.3%) and intronic lncRNAs (2.9%). Compared with protein-coding RNAs, pine lncRNAs are shorter, have lower expression, lower GC content and harbour fewer and shorter exons. A total of 164 differentially expressed (DE) lncRNAs were identified in response to F. circinatum infection in the inoculated versus mock-inoculated P. radiata seedlings. The predicted cis-regulated target genes of these pathogen-responsive lncRNAs were related to defence mechanisms such as kinase activity, phytohormone regulation, and cell wall reinforcement. Co-expression network analysis of DE lncRNAs, DE protein-coding RNAs and lncRNA target genes also indicated a potential network regulating pectinesterase activity and cell wall remodelling. This study presents the first analysis of conifer lncRNAs involved in the regulation of defence network and provides the basis for future functional characterizations of lncRNAs in relation to pine defence responses against F. circinatum.

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