scholarly journals The long non-coding RNA landscape of Candida yeast pathogens

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hrant Hovhannisyan ◽  
Toni Gabaldón

AbstractLong non-coding RNAs (lncRNAs) constitute a poorly studied class of transcripts with emerging roles in key cellular processes. Despite efforts to characterize lncRNAs across a wide range of species, these molecules remain largely unexplored in most eukaryotic microbes, including yeast pathogens of the Candida clade. Here, we analyze thousands of publicly available sequencing datasets to infer and characterize the lncRNA repertoires of five major Candida pathogens: Candida albicans, Candida tropicalis, Candida parapsilosis, Candida auris and Candida glabrata. Our results indicate that genomes of these species encode hundreds of lncRNAs that show levels of evolutionary constraint intermediate between those of intergenic genomic regions and protein-coding genes. Despite their low sequence conservation across the studied species, some lncRNAs are syntenic and are enriched in shared sequence motifs. We find co-expression of lncRNAs with certain protein-coding transcripts, hinting at potential functional associations. Finally, we identify lncRNAs that are differentially expressed during infection of human epithelial cells for four of the studied species. Our comprehensive bioinformatic analyses of Candida lncRNAs pave the way for future functional characterization of these transcripts.

Author(s):  
Erik S Wright

Abstract Summary Non-coding RNAs are often neglected during genome annotation due to their difficulty of detection relative to protein coding genes. FindNonCoding takes a pattern mining approach to capture the essential sequence motifs and hairpin loops representing a non-coding RNA family and quickly identify matches in genomes. FindNonCoding was designed for ease of use and accurately finds non-coding RNAs with a low false discovery rate. Availability FindNonCoding is implemented within the DECIPHER package (v2.19.3) for R (v4.1) available from Bioconductor. Pre-trained models of common non-coding RNA families are included for bacteria, archaea, and eukarya. Supplementary information Supplementary data are available at Bioinformatics online.


Planta ◽  
2020 ◽  
Vol 252 (5) ◽  
Author(s):  
Li Chen ◽  
Qian-Hao Zhu ◽  
Kerstin Kaufmann

Abstract Main conclusion Long non-coding RNAs modulate gene activity in plant development and stress responses by various molecular mechanisms. Abstract Long non-coding RNAs (lncRNAs) are transcripts larger than 200 nucleotides without protein coding potential. Computational approaches have identified numerous lncRNAs in different plant species. Research in the past decade has unveiled that plant lncRNAs participate in a wide range of biological processes, including regulation of flowering time and morphogenesis of reproductive organs, as well as abiotic and biotic stress responses. LncRNAs execute their functions by interacting with DNA, RNA and protein molecules, and by modulating the expression level of their targets through epigenetic, transcriptional, post-transcriptional or translational regulation. In this review, we summarize characteristics of plant lncRNAs, discuss recent progress on understanding of lncRNA functions, and propose an experimental framework for functional characterization.


2021 ◽  
Author(s):  
Tatiana Kulikova ◽  
Antonina Maslova ◽  
Polina Starshova ◽  
Juan Sebastian Rodriguez ◽  
Alla Krasikova

In diplotene oocyte nuclei of all vertebrate species, except mammals, chromosomes lack interchromosomal contacts and chromatin is linearly compartmentalized into distinct chromomere-loop complexes forming lampbrush chromosomes. However, the mechanisms underlying the formation of chromomere-loop complexes remain unexplored. Here we aimed to juxtapose somatic topologically associating domains (TADs), recently identified in chicken embryonic fibroblasts, with chromomere-loop complexes in lampbrush meiotic chromosomes. By measuring 3D-distances and colocalization between linear equidistantly located genomic loci, positioned within one TAD or separated by a TAD border, we confirmed the presence of predicted TADs in chicken embryonic fibroblast nuclei. Using three-colored FISH with BAC probes we mapped equidistant genomic regions included in several sequential somatic TADs on isolated chicken lampbrush chromosomes. Eight genomic regions, each comprising two or three somatic TADs, were mapped to non-overlapping neighboring lampbrush chromatin domains - lateral loops, chromomeres or chromomere-loop complexes. Genomic loci from the neighboring somatic TADs could localize in one lampbrush chromomere-loop complex, while genomic loci belonging to the same somatic TAD could be localized in neighboring lampbrush chromomere-loop domains. In addition, FISH-mapping of BAC probes to the nascent transcripts on the lateral loops indicates transcription of at least 17 protein-coding genes and 2 non-coding RNA genes during the lampbrush stage of chicken oogenesis, including genes involved in oocyte maturation and early embryo development.


2021 ◽  
Author(s):  
Hanneke Vlaming ◽  
Claudia A Mimoso ◽  
Benjamin JE Martin ◽  
Andrew R Field ◽  
Karen Adelman

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.


1999 ◽  
Vol 73 (10) ◽  
pp. 8741-8749 ◽  
Author(s):  
Juhana Santti ◽  
Timo Hyypiä ◽  
Leena Kinnunen ◽  
Mika Salminen

ABSTRACT Human enteroviruses consist of more than 60 serotypes, reflecting a wide range of evolutionary divergence. They have been genetically classified into four clusters on the basis of sequence homology in the coding region of the single-stranded RNA genome. To explore further the genetic relationships between human enteroviruses and to characterize the evolutionary mechanisms responsible for variation, previously sequenced genomes were subjected to detailed comparison. Bootstrap and genetic similarity analyses were used to systematically scan the alignments of complete genomic sequences. Bootstrap analysis provided evidence from an early recombination event at the junction of the 5′ noncoding and coding regions of the progenitors of the current clusters. Analysis within the genetic clusters indicated that enterovirus prototype strains include intraspecies recombinants. Recombination breakpoints were detected in all genomic regions except the capsid protein coding region. Our results suggest that recombination is a significant and relatively frequent mechanism in the evolution of enterovirus genomes.


2019 ◽  
Vol 5 (1) ◽  
pp. 15 ◽  
Author(s):  
Shrey Gandhi ◽  
Frank Ruehle ◽  
Monika Stoll

Cardiovascular diseases (CVDs) affect the heart and the vascular system with a high prevalence and place a huge burden on society as well as the healthcare system. These complex diseases are often the result of multiple genetic and environmental risk factors and pose a great challenge to understanding their etiology and consequences. With the advent of next generation sequencing, many non-coding RNA transcripts, especially long non-coding RNAs (lncRNAs), have been linked to the pathogenesis of CVD. Despite increasing evidence, the proper functional characterization of most of these molecules is still lacking. The exploration of conservation of sequences across related species has been used to functionally annotate protein coding genes. In contrast, the rapid evolutionary turnover and weak sequence conservation of lncRNAs make it difficult to characterize functional homologs for these sequences. Recent studies have tried to explore other dimensions of interspecies conservation to elucidate the functional role of these novel transcripts. In this review, we summarize various methodologies adopted to explore the evolutionary conservation of cardiovascular non-coding RNAs at sequence, secondary structure, syntenic, and expression level.


2007 ◽  
Vol 189 (8) ◽  
pp. 3133-3139 ◽  
Author(s):  
J. N. Copp ◽  
A. A. Roberts ◽  
M. A. Marahiel ◽  
B. A. Neilan

ABSTRACT The phosphopantetheinyl transferases (PPTs) are a superfamily of essential enzymes required for the synthesis of a wide range of compounds, including fatty acids, polyketides, and nonribosomal peptide metabolites. These enzymes activate carrier proteins in specific biosynthetic pathways by transfer of a phosphopantetheinyl moiety. The diverse PPT superfamily can be divided into two families based on specificity and conserved sequence motifs. The first family is typified by the Escherichia coli acyl carrier protein synthase (AcpS), which is involved in fatty acid synthesis. The prototype of the second family is the broad-substrate-range PPT Sfp, which is required for surfactin biosynthesis in Bacillus subtilis. Most cyanobacteria do not encode an AcpS-like PPT, and furthermore, some of their Sfp-like PPTs belong to a unique phylogenetic subgroup defined by the PPTs involved in heterocyst differentiation. Here, we describe the first functional characterization of a cyanobacterial PPT based on a structural analysis and subsequent functional analysis of the Nodularia spumigena NSOR10 PPT. Southern hybridizations suggested that this enzyme may be the only PPT encoded in the N. spumigena NSOR10 genome. Expression and enzyme characterization showed that this PPT was capable of modifying carrier proteins resulting from both heterocyst glycoplipid synthesis and nodularin toxin synthesis. Cyanobacteria are a unique and vast source of bioactive metabolites; therefore, an understanding of cyanobacterial PPTs is important in order to harness the biotechnological potential of cyanobacterial natural products.


2021 ◽  
Vol 22 (4) ◽  
pp. 1703
Author(s):  
Nicole Raad ◽  
Hannes Luidalepp ◽  
Michel Fasnacht ◽  
Norbert Polacek

Almost two-thirds of the microbiome’s biomass has been predicted to be in a non-proliferating, and thus dormant, growth state. It is assumed that dormancy goes hand in hand with global downregulation of gene expression. However, it remains largely unknown how bacteria manage to establish this resting phenotype at the molecular level. Recently small non-protein-coding RNAs (sRNAs or ncRNAs) have been suggested to be involved in establishing the non-proliferating state in bacteria. Here, we have deep sequenced the small transcriptome of Escherichia coli in the exponential and stationary phases and analyzed the resulting reads by a novel biocomputational pipeline STARPA (Stable RNA Processing Product Analyzer). Our analysis reveals over 12,000 small transcripts enriched during both growth stages. Differential expression analysis reveals distinct sRNAs enriched in the stationary phase that originate from various genomic regions, including transfer RNA (tRNA) fragments. Furthermore, expression profiling by Northern blot and RT-qPCR analyses confirms the growth phase-dependent expression of several enriched sRNAs. Our study adds to the existing repertoire of bacterial sRNAs and suggests a role for some of these small molecules in establishing and maintaining stationary phase as well as the bacterial stress response. Functional characterization of these detected sRNAs has the potential of unraveling novel regulatory networks central for stationary phase biology.


2019 ◽  
Author(s):  
Sergei Yu. Funikov ◽  
Alexander P. Rezvykh ◽  
Dina A. Kulikova ◽  
Elena S. Zelentsova ◽  
Lyubov N. Chuvakova ◽  
...  

AbstractPericentric heterochromatin in Drosophila is generally composed of repetitive DNA forming a transcriptionally repressive environment. Nevertheless, dozens of genes were embedded into pericentric genome regions during evolution of Drosophilidae lineage and retained functional activity. However, factors that contribute to “immunity” of these gene loci to transcriptional silencing remain unknown. Here, we investigated molecular evolution of the essential Myb and Ranbp16 genes. These protein-coding genes reside in euchromatic loci of chromosome X in D. melanogaster and related species, while in other studied Drosophila species, including evolutionary distant ones, they are located in genomic regions highly enriched with the remnants of transposable elements (TEs), suggesting their heterochromatic nature and location. The promoter region of Myb exhibits a conserved structure throughout the Drosophila phylogeny and carries motifs for binding of chromatin remodeling factors, including insulator BEAF-32, regardless of eu- or heterochromatic surroundings. Importantly, BEAF-32 occupies not only the promoter region of Myb but is also found in the vicinity of transcriptional start sites (TSS) of Ranbp16 gene as well as in a wide range of genes located in the contrasting chromatin types in D. melanogaster and D. virilis, denoting the boundary of the nucleosome-free region available for RNA polymerase II recruitment and the surrounding heterochromatin. We also find that along with BEAF-32, insulators dCTCF and GAF are enriched at the TSS of heterochromatic genes in D. melanogaster. Thus, we propose that insulator proteins contribute to gene expression in the heterochromatic environment and, hence, facilitate the evolutionary repositioning of gene loci into heterochromatin.Author summaryHeterochromatin in Drosophila is generally associated with transcriptional silencing. Nevertheless, hundreds of essential genes have been identified in the pericentric heterochromatin of Drosophila melanogaster. Interestingly, genes embedded in pericentric heterochromatin of D. melanogaster may occupy different genomic loci, euchromatic or heterochromatic, due to repositioning in the course of evolution of Drosophila species. By surveying factors that contribute to the normal functioning of the relocated genes in distant Drosophila species, i.e. D. melanogaster and D. virilis, we identify certain insulator proteins (e.g.BEAF-32) that facilitate the expression of heterochromatic genes in spite of the repressive environment.


2021 ◽  
Vol 33 (2) ◽  
pp. 157-165
Author(s):  
Xuanzong Guo ◽  
Uwe Ohler ◽  
Ferah Yildirim

Abstract Genetic variants associated with human diseases are often located outside the protein coding regions of the genome. Identification and functional characterization of the regulatory elements in the non-coding genome is therefore of crucial importance for understanding the consequences of genetic variation and the mechanisms of disease. The past decade has seen rapid progress in high-throughput analysis and mapping of chromatin accessibility, looping, structure, and occupancy by transcription factors, as well as epigenetic modifications, all of which contribute to the proper execution of regulatory functions in the non-coding genome. Here, we review the current technologies for the definition and functional validation of non-coding regulatory regions in the genome.


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