scholarly journals Characterization of RNA content in individual phase-separated coacervate microdroplets

2021 ◽  
Author(s):  
Damian Wollny ◽  
Benjamin Vernot ◽  
Jie Wang ◽  
Maria Hondele ◽  
Anthony Hyman ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Rna World ◽  
Sequence Similarity ◽  
Central Component ◽  
Sequence Motifs ◽  
High Sequence Similarity ◽  
Specific Sequence ◽  
Rna Content ◽  
Wide Range

AbstractLiquid-liquid phase separation or condensation is a form of macromolecular compartmentalization. Condensates formed by complex coacervation were hypothesized to have played a crucial part during the origin-of-life. In living cells, condensation organizes biomolecules into a wide range of membraneless compartments. Although RNA is a key component of condensation in cells and the central component of the RNA world hypothesis, little is known about what determines RNA accumulation in condensates and how single condensates differ in their RNA composition. Therefore, we developed an approach to read the RNA content from single condensates using high-throughput sequencing. We find that RNAs which are enriched for specific sequence motifs efficiently accumulate in condensates. These motifs show high sequence similarity to short interspersed elements (SINEs). We observed similar results for protein-derived condensates, demonstrating applicability across different in vitro reconstituted membraneless organelles. Thus, our results provide a new inroad to explore the RNA content of phase-separated droplets at single condensate resolution.

scholarly journals In VivoEfficacy of Anuran Trypsin Inhibitory Peptides against Staphylococcal Skin Infection and the Impact of Peptide Cyclization

2015 ◽  
Vol 59 (4) ◽  
pp. 2113-2121 ◽  
Author(s):  
U. Malik ◽  
O. N. Silva ◽  
I. C. M. Fensterseifer ◽  
L. Y. Chan ◽  
R. J. Clark ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Cyclic Peptide ◽  
Sequence Similarity ◽  
Infection Model ◽  
Content Type ◽  
Wide Range ◽  
Inhibitory Activities ◽  
The Impact

ABSTRACTStaphylococcus aureusis a virulent pathogen that is responsible for a wide range of superficial and invasive infections. Its resistance to existing antimicrobial drugs is a global problem, and the development of novel antimicrobial agents is crucial. Antimicrobial peptides from natural resources offer potential as new treatments against staphylococcal infections. In the current study, we have examined the antimicrobial properties of peptides isolated from anuran skin secretions and cyclized synthetic analogues of these peptides. The structures of the peptides were elucidated by nuclear magnetic resonance (NMR) spectroscopy, revealing high structural and sequence similarity with each other and with sunflower trypsin inhibitor 1 (SFTI-1). SFTI-1 is an ultrastable cyclic peptide isolated from sunflower seeds that has subnanomolar trypsin inhibitory activity, and this scaffold offers pharmaceutically relevant characteristics. The five anuran peptides were nonhemolytic and noncytotoxic and had trypsin inhibitory activities similar to that of SFTI-1. They demonstrated weakin vitroinhibitory activities againstS. aureus, but several had strong antibacterial activities againstS. aureusin anin vivomurine wound infection model. pYR, an immunomodulatory peptide fromRana sevosa, was the most potent, with complete bacterial clearance at 3 mg · kg−1. Cyclization of the peptides improved their stability but was associated with a concomitant decrease in antimicrobial activity. In summary, these anuran peptides are promising as novel therapeutic agents for treating infections from a clinically resistant pathogen.

scholarly journals NADPH-dependent extracellular superoxide production is vital to photophysiology in the marine diatom Thalassiosira oceanica

2019 ◽  
Vol 116 (33) ◽  
pp. 16448-16453 ◽  
Author(s):  
Julia M. Diaz ◽  
Sydney Plummer ◽  
Colleen M. Hansel ◽  
Peter F. Andeer ◽  
Mak A. Saito ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Cell Types ◽  
Redox Balance ◽  
Superoxide Production ◽  
Marine Phytoplankton ◽  
Marine Diatom ◽  
High Sequence Similarity ◽  
Whole Cells ◽  
Wide Range ◽  
Diphenylene Iodonium

Reactive oxygen species (ROS) like superoxide drive rapid transformations of carbon and metals in aquatic systems and play dynamic roles in biological health, signaling, and defense across a diversity of cell types. In phytoplankton, however, the ecophysiological role(s) of extracellular superoxide production has remained elusive. Here, the mechanism and function of extracellular superoxide production by the marine diatom Thalassiosira oceanica are described. Extracellular superoxide production in T. oceanica exudates was coupled to the oxidation of NADPH. A putative NADPH-oxidizing flavoenzyme with predicted transmembrane domains and high sequence similarity to glutathione reductase (GR) was implicated in this process. GR was also linked to extracellular superoxide production by whole cells via quenching by the flavoenzyme inhibitor diphenylene iodonium (DPI) and oxidized glutathione, the preferred electron acceptor of GR. Extracellular superoxide production followed a typical photosynthesis-irradiance curve and increased by 30% above the saturation irradiance of photosynthesis, while DPI significantly impaired the efficiency of photosystem II under a wide range of light levels. Together, these results suggest that extracellular superoxide production is a byproduct of a transplasma membrane electron transport system that serves to balance the cellular redox state through the recycling of photosynthetic NADPH. This photoprotective function may be widespread, consistent with the presence of putative homologs to T. oceanica GR in other representative marine phytoplankton and ocean metagenomes. Given predicted climate-driven shifts in global surface ocean light regimes and phytoplankton community-level photoacclimation, these results provide implications for future ocean redox balance, ecological functioning, and coupled biogeochemical transformations of carbon and metals.

scholarly journals Using a Simple Cellular Assay to Map NES Motifs in Cancer-Related Proteins, Gain Insight into CRM1-Mediated NES Export, and Search for NES-Harboring Micropeptides

2020 ◽  
Vol 21 (17) ◽  
pp. 6341
Author(s):  
Maria Sendino ◽  
Miren Josu Omaetxebarria ◽  
Gorka Prieto ◽  
Jose Antonio Rodriguez
Keyword(s):  
Nuclear Export ◽  
Relevant Information ◽  
Sequence Motifs ◽  
Specific Sequence ◽  
Cellular Assay ◽  
Small Proteins ◽  
Binding Groove ◽  
Related Proteins ◽  
Insight Into

The nuclear export receptor CRM1 (XPO1) recognizes and binds specific sequence motifs termed nuclear export signals (NESs) in cargo proteins. About 200 NES motifs have been identified, but over a thousand human proteins are potential CRM1 cargos, and most of their NESs remain to be identified. On the other hand, the interaction of NES peptides with the “NES-binding groove” of CRM1 was studied in detail using structural and biochemical analyses, but a better understanding of CRM1 function requires further investigation of how the results from these in vitro studies translate into actual NES export in a cellular context. Here we show that a simple cellular assay, based on a recently described reporter (SRVB/A), can be applied to identify novel potential NESs motifs, and to obtain relevant information on different aspects of CRM1-mediated NES export. Using cellular assays, we first map 19 new sequence motifs with nuclear export activity in 14 cancer-related proteins that are potential CRM1 cargos. Next, we investigate the effect of mutations in individual NES-binding groove residues, providing further insight into CRM1-mediated NES export. Finally, we extend the search for CRM1-dependent NESs to a recently uncovered, but potentially vast, set of small proteins called micropeptides. By doing so, we report the first NES-harboring human micropeptides.

scholarly journals Point Mutations in Yeast CBF5 Can Abolish In Vivo Pseudouridylation of rRNA

1999 ◽  
Vol 19 (11) ◽  
pp. 7461-7472 ◽  
Author(s):  
Yeganeh Zebarjadian ◽  
Tom King ◽  
Maurille J. Fournier ◽  
Louise Clarke ◽  
John Carbon
Keyword(s):  
Catalytic Domain ◽  
Sequence Similarity ◽  
Point Mutations ◽  
Rrna Synthesis ◽  
Temperature Sensitive ◽  
In Vitro Mutagenesis ◽  
Sequence Motifs ◽  
Conserved Sequence

ABSTRACT In budding yeast (Saccharomyces cerevisiae), the majority of box H/ACA small nucleolar RNPs (snoRNPs) have been shown to direct site-specific pseudouridylation of rRNA. Among the known protein components of H/ACA snoRNPs, the essential nucleolar protein Cbf5p is the most likely pseudouridine (Ψ) synthase. Cbf5p has considerable sequence similarity to Escherichia coli TruBp, a known Ψ synthase, and shares the “KP” and “XLD” conserved sequence motifs found in the catalytic domains of three distinct families of known and putative Ψ synthases. To gain additional evidence on the role of Cbf5p in rRNA biosynthesis, we have used in vitro mutagenesis techniques to introduce various alanine substitutions into the putative Ψ synthase domain of Cbf5p. Yeast strains expressing these mutatedcbf5 genes in a cbf5Δ null background are viable at 25°C but display pronounced cold- and heat-sensitive growth phenotypes. Most of the mutants contain reduced levels of Ψ in rRNA at extreme temperatures. Substitution of alanine for an aspartic acid residue in the conserved XLD motif of Cbf5p (mutantcbf5D95A) abolishes in vivo pseudouridylation of rRNA. Some of the mutants are temperature sensitive both for growth and for formation of Ψ in the rRNA. In most cases, the impaired growth phenotypes are not relieved by transcription of the rRNA from a polymerase II-driven promoter, indicating the absence of polymerase I-related transcriptional defects. There is little or no abnormal accumulation of pre-rRNAs in these mutants, although preferential inhibition of 18S rRNA synthesis is seen in mutantcbf5D95A, which lacks Ψ in rRNA. A subset of mutations in the Ψ synthase domain impairs association of the altered Cbf5p proteins with selected box H/ACA snoRNAs, suggesting that the functional catalytic domain is essential for that interaction. Our results provide additional evidence that Cbf5p is the Ψ synthase component of box H/ACA snoRNPs and suggest that the pseudouridylation of rRNA, although not absolutely required for cell survival, is essential for the formation of fully functional ribosomes.

Genetic characteristics of bla NDM-1-positive plasmid in Citrobacter freundii isolate separated from a clinical infectious patient

2013 ◽  
Vol 62 (9) ◽  
pp. 1332-1337 ◽  
Author(s):  
Xiao-Xing Du ◽  
Jian-Feng Wang ◽  
Ying Fu ◽  
Feng Zhao ◽  
Yan Chen ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Sequence Similarity ◽  
Blot Hybridization ◽  
Variable Region ◽  
Southern Blot Hybridization ◽  
Potential Threat ◽  
High Sequence Similarity ◽  
S1 Nuclease ◽  
Genetic Characteristics ◽  
Clinical Patient

This study reports an infectious case involving an NDM-1-producing Citrobacter freundii and further explored the potential threat of the bla NDM-1 gene by analysing the characteristics of the NDM-1-encoding plasmid sequence. A bla NDM-1-positive C. freundii with high resistance to carbapenems was separated from a clinical patient suffering from a urinary tract infection. S1 nuclease-based plasmid analysis followed by Southern blot hybridization, a conjugation experiment and electrotransformation confirmed that the bla NDM-1 gene was located on a plasmid. High-throughput sequencing of the bla NDM-1-postive plasmid (pCFNDM-CN) showed that it was a 54 kb IncX-type plasmid and contained a backbone region and a variable region with two β-lactamase genes (bla NDM-1 and bla SHV-12). The NDM-1 composite transposon in the variable region was surrounded by IS26 and IS5-truncated ISAba125, and shared a high sequence similarity to the bla NDM-1 surrounding structure in Acinetobacter spp. Our research suggested that the NDM-1 composite transposon might play an essential role in mobilization of the bla NDM-1 gene from Acinetobacter spp. to Enterobacteriaceae.

scholarly journals Screening thousands of transcribed coding and non-coding regions reveals sequence determinants of RNA polymerase II elongation potential

2021 ◽  
Author(s):  
Hanneke Vlaming ◽  
Claudia A Mimoso ◽  
Benjamin JE Martin ◽  
Andrew R Field ◽  
Karen Adelman
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
High Throughput Sequencing ◽  
Messenger Rnas ◽  
Sequence Motifs ◽  
Specific Sequence ◽  
Protein Coding ◽  
Non Coding Rna ◽  
The Impact

Organismal growth and development rely on RNA Polymerase II (RNAPII) synthesizing the appropriate repertoire of messenger RNAs (mRNAs) from protein-coding genes. Productive elongation of full-length transcripts is essential for mRNA function, however what determines whether an engaged RNAPII molecule will terminate prematurely or transcribe processively remains poorly understood. Notably, despite a common process for transcription initiation across RNAPII-synthesized RNAs, RNAPII is highly susceptible to termination when transcribing non-coding RNAs such as upstream antisense RNAs (uaRNAs) and enhancers RNAs (eRNAs), suggesting that differences arise during RNAPII elongation. To investigate the impact of transcribed sequence on elongation potential, we developed a method to screen the effects of thousands of INtegrated Sequences on Expression of RNA and Translation using high-throughput sequencing (INSERT-seq). We found that higher AT content in uaRNAs and eRNAs, rather than specific sequence motifs, underlies the propensity for RNAPII termination on these transcripts. Further, we demonstrate that 5' splice sites exert both splicing-dependent and autonomous, splicing-independent stimulation of transcription, even in the absence of polyadenylation signals. Together, our results reveal a potent role for transcribed sequence in dictating gene output at mRNA and non-coding RNA loci, and demonstrate the power of INSERT-seq towards illuminating these contributions.

scholarly journals Insights into Transcriptional Repression of the Homologous Toxin-Antitoxin Cassettes yefM-yoeB and axe-txe

2020 ◽  
Vol 21 (23) ◽  
pp. 9062
Author(s):  
Barbara Kędzierska ◽  
Katarzyna Potrykus ◽  
Agnieszka Szalewska-Pałasz ◽  
Beata Wodzikowska
Keyword(s):  
Transcriptional Repression ◽  
Transcription Initiation ◽  
Sequence Similarity ◽  
In Vitro Transcription ◽  
High Sequence Similarity ◽  
Sequence Composition ◽  
Repressor Complex ◽  
Transcriptional Fusions

Transcriptional repression is a mechanism which enables effective gene expression switch off. The activity of most of type II toxin-antitoxin (TA) cassettes is controlled in this way. These cassettes undergo negative autoregulation by the TA protein complex which binds to the promoter/operator sequence and blocks transcription initiation of the TA operon. Precise and tight control of this process is vital to avoid uncontrolled expression of the toxin component. Here, we employed a series of in vivo and in vitro experiments to establish the molecular basis for previously observed differences in transcriptional activity and repression levels of the pyy and pat promoters which control expression of two homologous TA systems, YefM-YoeB and Axe-Txe, respectively. Transcriptional fusions of promoters with a lux reporter, together with in vitro transcription, EMSA and footprinting assays revealed that: (1) the different sequence composition of the −35 promoter element is responsible for substantial divergence in strengths of the promoters; (2) variations in repression result from the TA repressor complex acting at different steps in the transcription initiation process; (3) transcription from an additional promoter upstream of pat also contributes to the observed inefficient repression of axe-txe module. This study provides evidence that even closely related TA cassettes with high sequence similarity in the promoter/operator region may employ diverse mechanisms for transcriptional regulation of their genes.

scholarly journals Structure and Sequence Determinants Governing the Interactions of RNAs with Influenza A Virus Non-Structural Protein NS1

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 947
Author(s):  
Alan Wacquiez ◽  
Franck Coste ◽  
Emmanuel Kut ◽  
Virginie Gaudon ◽  
Sascha Trapp ◽  
...  
Keyword(s):  
Influenza A ◽  
Rna Binding ◽  
3D Structure ◽  
Genetically Engineered ◽  
Phenotypic Characterization ◽  
Sequence Motifs ◽  
Structural Protein ◽  
Specific Sequence ◽  
Rna Interaction

The non-structural protein NS1 of influenza A viruses is an RNA-binding protein of which its activities in the infected cell contribute to the success of the viral cycle, notably through interferon antagonism. We have previously shown that NS1 strongly binds RNA aptamers harbouring virus-specific sequence motifs (Marc et al., Nucleic Acids Res. 41, 434–449). Here, we started out investigating the putative role of one particular virus-specific motif through the phenotypic characterization of mutant viruses that were genetically engineered from the parental strain WSN. Unexpectedly, our data did not evidence biological importance of the putative binding of NS1 to this specific motif (UGAUUGAAG) in the 3′-untranslated region of its own mRNA. Next, we sought to identify specificity determinants in the NS1-RNA interaction through interaction assays in vitro with several RNA ligands and through solving by X-ray diffraction the 3D structure of several complexes associating NS1′s RBD with RNAs of various affinities. Our data show that the RBD binds the GUAAC motif within double-stranded RNA helices with an apparent specificity that may rely on the sequence-encoded ability of the RNA to bend its axis. On the other hand, we showed that the RBD binds to the virus-specific AGCAAAAG motif when it is exposed in the apical loop of a high-affinity RNA aptamer, probably through a distinct mode of interaction that still requires structural characterization. Our data are consistent with more than one mode of interaction of NS1′s RBD with RNAs, recognizing both structure and sequence determinants.

scholarly journals Long-lasting Analgesia via Targetedin vivoEpigenetic Repression of Nav1.7

2019 ◽  
Author(s):  
Ana M. Moreno ◽  
Glaucilene F. Catroli ◽  
Fernando Alemán ◽  
Andrew Pla ◽  
Sarah A. Woller ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Genome Engineering ◽  
Therapeutic Potential ◽  
Sequence Similarity ◽  
Thermal Hyperalgesia ◽  
Loss Of Function ◽  
High Sequence Similarity ◽  
Inflammatory State

ABSTRACTCurrent treatments for chronic pain rely largely on opioids despite their unwanted side effects and risk of addiction. Genetic studies have identified in humans key targets pivotal to nociceptive processing, with the voltage-gated sodium channel, NaV1.7 (SCN9A), being perhaps the most promising candidate for analgesic drug development. Specifically, a hereditary loss-of-function mutation in NaV1.7 leads to insensitivity to pain without other neurodevelopmental alterations. However, the high sequence similarity between NaVsubtypes has frustrated efforts to develop selective inhibitors. Here, we investigated targeted epigenetic repression of NaV1.7 via genome engineering approaches based on clustered regularly interspaced short palindromic repeats (CRISPR)-dCas9 and zinc finger proteins as a potential treatment for chronic pain. Towards this end, we first optimized the efficiency of NaV1.7 repressionin vitroin Neuro2A cells, and then by the lumbar intrathecal route delivered both genome-engineering platforms via adeno-associated viruses (AAVs) to assess their effects in three mouse models of pain: carrageenan-induced inflammatory pain, paclitaxel-induced neuropathic pain and BzATP-induced pain. Our results demonstrate: one, effective repression of NaV1.7 in lumbar dorsal root ganglia; two, reduced thermal hyperalgesia in the inflammatory state; three, decreased tactile allodynia in the neuropathic state; and four, no changes in normal motor function. We anticipate this genomically scarless and non-addictivepainamelioration approach enablingLong-lastingAnalgesia viaTargetedin vivoEpigeneticRepression of Nav1.7, a methodology we dubpain LATER, will have significant therapeutic potential, such as for preemptive administration in anticipation of a pain stimulus (pre-operatively), or during an established chronic pain state.One sentence summaryIn situepigenome engineering approach for genomically scarless, durable, and non-addictive management of pain.

scholarly journals T-cell Receptor Diversity Estimates for Repertoires (TCRDivER) uses sequence similarity to find signatures of immune response

2021 ◽  
Author(s):  
Milena Vujović ◽  
Paolo Marcatili ◽  
Benny Chain ◽  
Joseph Kaplinsky ◽  
Thomas Lars Andresen
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Sequence Similarity ◽  
Cell Receptor ◽  
Sequence Motifs ◽  
Sequencing Data ◽  
Cell Repertoire ◽  
Specific Sequence ◽  
Clone Size ◽  
Diversity Estimates

AbstractWe propose TCRDivER, a global approach to T-cell repertoire comparison using diversity profiles sensitive to both clone size and sequence similarity. As immunotherapies improve, the long standing biological interest in connecting outcome with T cell receptor (TCR) repertoire status has become more urgent. Here we show that new insights can be extracted from high throughput repertoire sequencing data. Most current efforts focus on identification of immunisation-specific sequence motifs or on monitoring changes in frequency of individual clones. Applying TCRDivER to murine spleen samples shows it characterises an additional dimension of repertoire variation, beyond conventional diversity estimates, allowing distinction between immunised and non-immunised samples. We further apply TCRDivER to repertoires from human blood. In both cases we show characteristic relationships between repertoire features. These reveal biologically interpretable relationships between sequence similarity and clonal expansions. We thereby demonstrate a new tool for investigation in clinical and research applications.

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