scholarly journals Purine-responsive expression of the Leishmania donovani NT3 purine nucleobase transporter is mediated by a conserved RNA stem-loop

2020 ◽  
Author(s):  
M. Haley Licon ◽  
Phillip A. Yates
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Leishmania Donovani ◽  
Rna Binding ◽  
De Novo ◽  
Mutational Analysis ◽  
Rna Binding Proteins ◽  
Stem Loop ◽  
Sequence Elements

ABSTRACTThe ability to modulate gene expression in response to changes in the host environment is essential for survival of the kinetoplastid parasite Leishmania. Unlike most eukaryotes, gene expression in kinetoplastids is predominately regulated post-transcriptionally. Consequently, RNA-binding proteins (RBPs) and mRNA-encoded sequence elements serve as primary determinants of gene regulation in these organisms; however, few have been ascribed roles in specific stress-response pathways. Leishmania lack the capacity for de novo purine synthesis and must scavenge these essential nutrients from the host. Leishmania have evolved a robust stress response to withstand sustained periods of purine scarcity during their lifecycle. The purine nucleobase transporter, LdNT3, is among the most substantially upregulated proteins in purine-starved L. donovani. Here we report that the post-translational stability of the LdNT3 protein is unchanged in response to purine starvation. Instead, LdNT3 upregulation is primarily mediated by a 33 nucleotide (nt) sequence in the LdNT3 mRNA 3’-untranslated region that is predicted to adopt a stem-loop structure. While this sequence is highly conserved within the mRNAs of orthologous transporters in multiple kinetoplastid species, putative stem-loops from L. donovani and Trypanosoma brucei nucleobase transporter mRNAs are not functionally interchangeable for purine-responsive regulation. Through mutational analysis of the element, we demonstrate that species specificity is attributable to just three variant bases within the predicted loop. Finally, we provide evidence that the abundance of the trans-acting factor that binds the LdNT3 stem-loop in vivo is substantially higher than required for regulation of LdNT3 alone, implying a potential role in regulating other purine-responsive genes.

scholarly journals Purine-responsive expression of the Leishmania donovani NT3 purine nucleobase transporter is mediated by a conserved RNA stem–loop

2020 ◽  
Vol 295 (25) ◽  
pp. 8449-8459 ◽  
Author(s):  
M. Haley Licon ◽  
Phillip A. Yates
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Leishmania Donovani ◽  
Rna Binding ◽  
De Novo ◽  
Mutational Analysis ◽  
Rna Binding Proteins ◽  
Stem Loop ◽  
Sequence Elements

The ability to modulate gene expression in response to changes in the host environment is essential for survival of the kinetoplastid parasite Leishmania. Unlike most eukaryotes, gene expression in kinetoplastids is predominately regulated posttranscriptionally. Consequently, RNA-binding proteins and mRNA-encoded sequence elements serve as primary determinants of gene regulation in these organisms; however, few have defined roles in specific stress response pathways. Leishmania species cannot synthesize purines de novo and must scavenge these essential nutrients from the host. Leishmania have evolved a robust stress response to withstand sustained periods of purine scarcity during their life cycle. The purine nucleobase transporter LdNT3 is among the most substantially up-regulated proteins in purine-starved Leishmania donovani parasites. Here we report that the posttranslational stability of the LdNT3 protein is unchanged in response to purine starvation. Instead, LdNT3 up-regulation is primarily mediated by a 33-nucleotide-long sequence in the LdNT3 mRNA 3′ UTR that is predicted to adopt a stem–loop structure. Although this sequence is highly conserved within the mRNAs of orthologous transporters in multiple kinetoplastid species, putative stem–loops from L. donovani and Trypanosoma brucei nucleobase transporter mRNAs were not functionally interchangeable for purine-responsive regulation. Through mutational analysis of the element, we demonstrate that species specificity is attributable to just three variant bases within the predicted loop. Finally, we provide evidence that the abundance of the trans-acting factor that binds the LdNT3 stem–loop in vivo is substantially higher than required for regulation of LdNT3 alone, implying a potential role in regulating other purine-responsive genes.

scholarly journals Compendium of Methods to Uncover RNA-Protein Interactions In Vivo

2021 ◽  
Vol 4 (1) ◽  
pp. 22
Author(s):  
Mrinmoyee Majumder ◽  
Viswanathan Palanisamy
Keyword(s):  
Gene Expression ◽  
Protein Interactions ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Expression Patterns ◽  
Control Of Gene Expression ◽  
Regulatory Pathways ◽  
Advantages And Disadvantages ◽  
Protein Nucleic Acid

Control of gene expression is critical in shaping the pro-and eukaryotic organisms’ genotype and phenotype. The gene expression regulatory pathways solely rely on protein–protein and protein–nucleic acid interactions, which determine the fate of the nucleic acids. RNA–protein interactions play a significant role in co- and post-transcriptional regulation to control gene expression. RNA-binding proteins (RBPs) are a diverse group of macromolecules that bind to RNA and play an essential role in RNA biology by regulating pre-mRNA processing, maturation, nuclear transport, stability, and translation. Hence, the studies aimed at investigating RNA–protein interactions are essential to advance our knowledge in gene expression patterns associated with health and disease. Here we discuss the long-established and current technologies that are widely used to study RNA–protein interactions in vivo. We also present the advantages and disadvantages of each method discussed in the review.

scholarly journals Identification of proteins and miRNAs that specifically bind an mRNA in vivo

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Kathrin Theil ◽  
Koshi Imami ◽  
Nikolaus Rajewsky
Keyword(s):  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
Noncoding Rnas ◽  
Shotgun Proteomics ◽  
Small Rna Sequencing ◽  
C Elegans ◽  
Specific Transcript ◽  
Proteomics Approach

Abstract Understanding regulation of an mRNA requires knowledge of its regulators. However, methods for reliable de-novo identification of proteins binding to a particular RNA are scarce and were thus far only successfully applied to abundant noncoding RNAs in cell culture. Here, we present vIPR, an RNA-protein crosslink, RNA pulldown, and shotgun proteomics approach to identify proteins bound to selected mRNAs in C. elegans. Applying vIPR to the germline-specific transcript gld-1 led to enrichment of known and novel interactors. By comparing enrichment upon gld-1 and lin-41 pulldown, we demonstrate that vIPR recovers both common and specific RNA-binding proteins, and we validate DAZ-1 as a specific gld-1 regulator. Finally, combining vIPR with small RNA sequencing, we recover known and biologically important transcript-specific miRNA interactions, and we identify miR-84 as a specific interactor of the gld-1 transcript. We envision that vIPR will provide a platform for investigating RNA in vivo regulation in diverse biological systems.

scholarly journals Cip1 and Cip2 Are Novel RNA-Recognition-Motif Proteins That Counteract Csx1 Function during Oxidative Stress

2006 ◽  
Vol 17 (3) ◽  
pp. 1176-1183 ◽  
Author(s):  
Victoria Martín ◽  
Miguel A. Rodríguez-Gabriel ◽  
W. Hayes McDonald ◽  
Stephen Watt ◽  
John R. Yates ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Stress Response ◽  
Protein Identification ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Bzip Transcription Factor ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Control Of Gene Expression

Eukaryotic cells reprogram their global patterns of gene expression in response to stress. Recent studies in Schizosaccharomyces pombe showed that the RNA-binding protein Csx1 plays a central role in controlling gene expression during oxidative stress. It does so by stabilizing atf1+ mRNA, which encodes a subunit of a bZIP transcription factor required for gene expression during oxidative stress. Here, we describe two related proteins, Cip1 and Cip2, that were identified by multidimensional protein identification technology (MudPIT) as proteins that coprecipitate with Csx1. Cip1 and Cip2 are cytoplasmic proteins that have RNA recognition motifs (RRMs). Neither protein is essential for viability, but a cip1Δ cip2Δ strain grows poorly and has altered cellular morphology. Genetic epistasis studies and whole genome expression profiling show that Cip1 and Cip2 exert posttranscriptional control of gene expression in a manner that is counteracted by Csx1. Notably, the sensitivity of csx1Δ cells to oxidative stress and their inability to induce expression of Atf1-dependent genes are partially rescued by cip1Δ and cip2Δ mutations. This study emphasizes the importance of a modulated mRNA stability in the eukaryotic stress response pathways and adds new information to the role of RNA-binding proteins in the oxidative stress response.

scholarly journals Substrate Specificity of the TRAMP Nuclear Surveillance Complexes

2020 ◽  
Author(s):  
Clémentine Delan-Forino ◽  
Christos Spanos ◽  
Juri Rappsilber ◽  
David Tollervey
Keyword(s):  
Gene Expression ◽  
Mass Spectrometry ◽  
Binding Sites ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Rna Binding Protein ◽  
Rna Helicase ◽  
Nuclear Rna ◽  
Rna Exosome

ABSTRACTDuring nuclear surveillance in yeast, the RNA exosome functions together with the TRAMP complexes. These include the DEAH-box RNA helicase Mtr4 together with an RNA-binding protein (Air1 or Air2) and a poly(A) polymerase (Trf4 or Trf5). To better determine how RNA substrates are targeted, we analyzed protein and RNA interactions for TRAMP components. Mass spectrometry identified three distinct TRAMP complexes formed in vivo. These complexes preferentially assemble on different classes of transcripts. Unexpectedly, on many substrates, including pre-rRNAs and pre-mRNAs, binding specificity was apparently conferred by Trf4 and Trf5. Clustering of mRNAs by TRAMP association showed co-enrichment for mRNAs with functionally related products, supporting the significance of surveillance in regulating gene expression. We compared binding sites of TRAMP components with multiple nuclear RNA binding proteins, revealing preferential colocalization of subsets of factors. TRF5 deletion reduced Mtr4 recruitment and increased RNA abundance for mRNAs specifically showing high Trf5 binding.

scholarly journals Comprehensive analysis of translation from overexpressed circular RNAs reveals pervasive translation from linear transcripts

2020 ◽  
Vol 48 (18) ◽  
pp. 10368-10382 ◽  
Author(s):  
Hung Ho-Xuan ◽  
Petar Glažar ◽  
Claudia Latini ◽  
Kevin Heizler ◽  
Jacob Haase ◽  
...  
Keyword(s):  
Rna Binding ◽  
Mutational Analysis ◽  
Rna Binding Proteins ◽  
Open Reading Frames ◽  
Circular Rnas ◽  
Internal Ribosome Entry ◽  
Functional Studies ◽  
Sequence Elements ◽  
Endogenous Proteins ◽  
Functional Relevance

Abstract Circular RNAs (circRNAs) encompass a widespread and conserved class of RNAs, which are generated by back-splicing of downstream 5′ to upstream 3′ splice sites. CircRNAs are tissue-specific and have been implicated in diseases including cancer. They can function as sponges for microRNAs (miRNAs) or RNA binding proteins (RBPs), for example. Moreover, some contain open reading frames (ORFs) and might be translated. The functional relevance of such peptides, however, remains largely elusive. Here, we report that the ORF of circZNF609 is efficiently translated when expressed from a circZNF609 overexpression construct. However, endogenous proteins could not be detected. Moreover, initiation of circZNF609 translation is independent of m6A-generating enzyme METTL3 or RNA sequence elements such as internal ribosome entry sites (IRESs). Surprisingly, a comprehensive mutational analysis revealed that deletion constructs, which are deficient in producing circZNF609, still generate the observed protein products. This suggests that the apparent circZNF609 translation originates from trans-splicing by-products of the overexpression plasmids and underline that circRNA overexpression constructs need to be evaluated carefully, particularly when functional studies are performed.

scholarly journals Global identification of RsmA/N binding sites in Pseudomonas aeruginosa by in vivo UV CLIP-seq

2020 ◽  
Author(s):  
Kotaro Chihara ◽  
Lars Barquist ◽  
Kenichi Takasugi ◽  
Naohiro Noda ◽  
Satoshi Tsuneda
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Binding Sites ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Chronic Infections ◽  
Uv Crosslinking ◽  
Rna Interaction

ABSTRACTPosttranscriptional regulation of gene expression in bacteria is performed by a complex and hierarchical signaling cascade. Pseudomonas aeruginosa harbors two redundant RNA-binding proteins RsmA/RsmN (RsmA/N), which play a critical role in balancing acute and chronic infections. However, in vivo binding sites on target transcripts and the overall impact on the physiology remains unclear. In this study, we applied in vivo UV crosslinking immunoprecipitation followed by RNA-sequencing (UV CLIP-seq) to detect RsmA/N binding sites at single-nucleotide resolution and mapped more than 500 peaks to approximately 400 genes directly bound by RsmA/N in P. aeruginosa. This also demonstrated the ANGGA sequence in apical loops skewed towards 5’UTRs as a consensus motif for RsmA/N binding. Genetic analysis combined with CLIP-seq results identified previously unrecognized RsmA/N targets involved in LPS modification. Moreover, the small non-coding RNAs RsmY/RsmZ, which sequester RsmA/N away from target mRNAs, are positively regulated by the RsmA/N-mediated translational repression of hptB, encoding a histidine phosphotransfer protein, and cafA, encoding a cytoplasmic axial filament protein, thus providing a possible mechanistic explanation for homeostasis of the Rsm system. Our findings present the global RsmA/N-RNA interaction network that exerts pleiotropic effects on gene expression in P. aeruginosa.IMPORTANCEThe ubiquitous bacterium Pseudomonas aeruginosa is notorious as an opportunistic pathogen causing life-threatening acute and chronic infections in immunocompromised patients. P. aeruginosa infection processes are governed by two major gene regulatory systems, namely, the GacA/GacS (GacAS) two-component system and the RNA-binding proteins RsmA/RsmN (RsmA/N). RsmA/N basically function as a translational repressor or activator directly by competing with the ribosome. In this study, we identified hundreds of RsmA/N regulatory target RNAs and the consensus motifs for RsmA/N bindings by UV crosslinking in vivo. Moreover, our CLIP-seq revealed that RsmA/N posttranscriptionally regulate cell wall organization and exert feedback control on GacAS-RsmA/N systems. Many genes including small regulatory RNAs identified in this study are attractive targets for further elucidating the regulatory mechanisms of RsmA/N in P. aeruginosa.

scholarly journals Primary and Secondary Sequence Structure Requirements for Recognition and Discrimination of Target RNAs by Pseudomonas aeruginosa RsmA and RsmF

2016 ◽  
Vol 198 (18) ◽  
pp. 2458-2469 ◽  
Author(s):  
Kayley H. Schulmeyer ◽  
Manisha R. Diaz ◽  
Thomas B. Bair ◽  
Wes Sanders ◽  
Cindy J. Gode ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Binding Sites ◽  
Posttranscriptional Regulation ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Consensus Sequence ◽  
Stem Loop ◽  
Content Type

ABSTRACTCsrA family RNA-binding proteins are widely distributed in bacteria and regulate gene expression at the posttranscriptional level.Pseudomonas aeruginosahas a canonical member of the CsrA family (RsmA) and a novel, structurally distinct variant (RsmF). To better understand RsmF binding properties, we performed parallel systematic evolution of ligands by exponential enrichment (SELEX) experiments for RsmA and RsmF. The initial target library consisted of 62-nucleotide (nt) RNA transcripts with central cores randomized at 15 sequential positions. Most targets selected by RsmA and RsmF were the expected size and shared a common consensus sequence (CANGGAYG) that was positioned in a hexaloop region of the stem-loop structure. RsmA and RsmF also selected for longer targets (≥96 nt) that were likely generated by rare PCR errors. Most of the long targets contained two consensus-binding sites. Representative short (single consensus site) and long (two consensus sites) targets were tested for RsmA and RsmF binding. Whereas RsmA bound the short targets with high affinity, RsmF was unable to bind the same targets. RsmA and RsmF both bound the long targets. Mutation of either consensus GGA site in the long targets reduced or eliminated RsmF binding, suggesting a requirement for two tandem binding sites. Conversely, RsmA bound long targets containing only a single GGA site with unaltered affinity. The RsmF requirement for two binding sites was confirmed withtssA1, anin vivoregulatory target of RsmA and RsmF. Our findings suggest that RsmF binding requires two GGA-containing sites, while RsmA binding requirements are less stringent.IMPORTANCEThe CsrA family of RNA-binding proteins is widely conserved in bacteria and plays important roles in the posttranscriptional regulation of protein synthesis.P. aeruginosahas two CsrA proteins, RsmA and RsmF. Although RsmA and RsmF share a few RNA targets, RsmF is unable to bind to other targets recognized by RsmA. The goal of the present study was to better understand the basis for differential binding by RsmF. Our data indicate that RsmF binding requires target RNAs with two consensus-binding sites, while RsmA recognizes targets with just a single binding site. This information should prove useful to future efforts to define the RsmF regulon and its contribution toP. aeruginosaphysiology and virulence.

scholarly journals Modeling RNA-binding protein specificity in vivo by precisely registering protein-RNA crosslink sites

2018 ◽  
Author(s):  
Huijuan Feng ◽  
Suying Bao ◽  
Sebastien M. Weyn-Vanhentenryck ◽  
Aziz Khan ◽  
Justin Wong ◽  
...  
Keyword(s):  
Binding Sites ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Specificity ◽  
Computational Method ◽  
Sr Protein ◽  
Genome Wide ◽  
Sequence Elements ◽  
Nucleotide Resolution

AbstractRNA-binding proteins (RBPs) regulate post-transcriptional gene expression by recognizing short and degenerate sequence elements in their target transcripts. Despite the expanding list of RBPs with in vivo binding sites mapped genomewide using crosslinking and immunoprecipitation (CLIP), defining precise RBP binding specificity remains challenging. We previously demonstrated that the exact protein-RNA crosslink sites can be mapped using CLIP data at single-nucleotide resolution and observed that crosslinking frequently occurs at specific positions in RBP motifs. Here we have developed a computational method, named mCross, to jointly model RBP binding specificity while precisely registering the crosslinking position in motif sites. We applied mCross to 112 RBPs using ENCODE eCLIP data and validated the reliability of the resulting motifs by genome-wide analysis of allelic binding sites also detected by CLIP. We found that the prototypical SR protein SRSF1 recognizes GGA clusters to regulate splicing in a much larger repertoire of transcripts than previously appreciated.

scholarly journals TriPepSVM - de novo prediction of RNA-binding proteins based on short amino acid motifs

2018 ◽  
Author(s):  
Annkatrin Bressin ◽  
Roman Schulte-Sasse ◽  
Davide Figini ◽  
Erika C Urdaneta ◽  
Benedikt M Beckmann ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
Low Complexity ◽  
Structural Features ◽  
Support Vector ◽  
String Kernels ◽  
Rna Binders

In recent years hundreds of novel RNA-binding proteins (RBPs) have been identified leading to the discovery of novel RNA-binding domains (RBDs). Furthermore, unstructured or disordered low-complexity regions of RBPs have been identified to play an important role in interactions with nucleic acids. However, these advances in understanding RBPs are limited mainly to eukaryotic species and we only have limited tools to faithfully predict RNA-binders from bacteria. Here, we describe a support vector machine (SVM)-based method, called TriPepSVM, for the classification of RNA-binding proteins and non-RBPs. TriPepSVM applies string kernels to directly handle protein sequences using tri-peptide frequencies. Testing the method in human and bacteria, we find that several RBP-enriched tripeptides occur more often in structurally disordered regions of RBPs. TriPepSVM outperforms existing applications, which consider classical structural features of RNA-binding or homology, in the task of RBP prediction in both human and bacteria. Finally, we predict 66 novel RBPs in Salmonella Typhimurium and validate the bacterial proteins ClpX, DnaJ and UbiG to associate with RNA in vivo.

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