scholarly journals The Mammalian Kalrn Locus Gives Rise to Several Novel Long Non-coding RNAs

Author(s):  
Muneesh Pal ◽  
Divya Chaubey ◽  
Mohit Tanwar ◽  
Beena Pillai

Abstract The Kalrn gene encodes several multi-domain protein isoforms that localise to neuronal synapses, and play dynamic roles in shaping axonal outgrowth, dendrite morphology and dendritic spine re-modelling. The genomic locus is implicated in several neurodevelopmental and neuropsychiatric diseases including autism, schizophrenia and bipolar disease. Mutations in the coding regions, inherited in a classical Mendelian manner, have also been implicated in certain forms of autism and intellectual disability. At the molecular level, the protein isoforms, encoded by reported transcript isoforms, share some core domains arising from the central exons, while other domains, especially towards the C terminal may be selectively incorporated. This heterogeneity seems to confer the ability to grow and retract dendritic spines, thus making Kalirin a critical and dynamic player in dendritogenesis. We have previously shown that in the zebrafish genome, a novel brain specific non-coding RNA arising from the 5’ end of the Kalirin gene, durga regulates neuronal morphology. In search of the mammalian equivalent, we characterized the mammalian Kalrn loci in detail, annotating multiple novel non-coding RNAs, including linear and circular variants, through analysis of transcriptomics data and experimental approaches. By comparing the mouse and human loci and studying the expression of the novel lncRNAs arising from the locus during differentiation of primary cortical neurons in culture, we show that certain non-coding RNAs arising from the locus show a temporal expression profile that coincides with a subset of Kalirin protein coding isoforms. In humans, mouse and zebrafish the 5’end of the Kalrn locus gives rise to a chromatin associated lncRNA that is present in adult ovaries besides being expressed during brain development and in certain regions of the adult brain. Besides correcting some of the annotations available in public databases, we propose that this lncRNA arising from the 5’end of the Kalrn locus is the mammalian ortholog of zebrafish lncRNA durga.

2019 ◽  
Author(s):  
Jason Talkish ◽  
Haller Igel ◽  
Rhonda J. Perriman ◽  
Lily Shiue ◽  
Sol Katzman ◽  
...  

AbstractIntrons are a prevalent feature of eukaryotic genomes, yet their origins and contributions to genome function and evolution remain mysterious. In budding yeast, repression of the highly transcribed intron-containing ribosomal protein genes (RPGs) globally increases splicing of non-RPG transcripts through reduced competition for the spliceosome. We show that under these “hungry spliceosome” conditions, splicing occurs at more than 150 previously unannotated locations we call protointrons that do not overlap known introns. Protointrons use a less constrained set of splice sites and branchpoints than standard introns, including in one case AT-AC in place of GT-AG. Protointrons are not conserved in all closely related species, suggesting that most are not under selection. Some are found in non-coding RNAs (e. g. CUTs and SUTs), where they may contribute to the creation of new genes. Others are found across boundaries between noncoding and coding sequences, or within coding sequences, where they offer pathways to the creation of new protein variants, or new regulatory controls for existing genes. We define protointrons as (1) nonconserved intron-like sequences that are (2) infrequently spliced, and importantly (3) are not currently understood to contribute to gene expression or regulation in the way that standard introns function. A very few protointrons in S. cerevisiae challenge this classification by their increased splicing frequency and potential function, consistent with the proposed evolutionary process of “intronization”, whereby new standard introns are created. This snapshot of intron evolution highlights the important role of the spliceosome in the expansion of transcribed genomic sequence space, providing a pathway for the rare events that may lead to the birth of new eukaryotic genes and the refinement of existing gene function.Author SummaryThe protein coding information in eukaryotic genes is broken by intervening sequences called introns that are removed from RNA during transcription by a large protein-RNA complex called the spliceosome. Where introns come from and how the spliceosome contributes to genome evolution are open questions. In this study, we find more than 150 new places in the yeast genome that are recognized by the spliceosome and spliced out as introns. Since they appear to have arisen very recently in evolution by sequence drift and do not appear to contribute to gene expression or its regulation, we call these protointrons. Protointrons are found in both protein-coding and non-coding RNAs and are not efficiently removed by the splicing machinery. Although most protointrons are not conserved, a few are spliced more efficiently, and are located where they might begin to play functional roles in gene expression, as predicted by the proposed process of intronization. The challenge now is to understand how spontaneously appearing splicing events like protointrons might contribute to the creation of new genes, new genetic controls, and new protein isoforms as genomes evolve.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Garima Bhatia ◽  
Santosh K. Upadhyay ◽  
Anuradha Upadhyay ◽  
Kashmir Singh

Abstract Background Long non-coding RNAs (lncRNAs) are regulatory transcripts of length > 200 nt. Owing to the rapidly progressing RNA-sequencing technologies, lncRNAs are emerging as considerable nodes in the plant antifungal defense networks. Therefore, we investigated their role in Vitis vinifera (grapevine) in response to obligate biotrophic fungal phytopathogens, Erysiphe necator (powdery mildew, PM) and Plasmopara viticola (downy mildew, DM), which impose huge agro-economic burden on grape-growers worldwide. Results Using computational approach based on RNA-seq data, 71 PM- and 83 DM-responsive V. vinifera lncRNAs were identified and comprehensively examined for their putative functional roles in plant defense response. V. vinifera protein coding sequences (CDS) were also profiled based on expression levels, and 1037 PM-responsive and 670 DM-responsive CDS were identified. Next, co-expression analysis-based functional annotation revealed their association with gene ontology (GO) terms for ‘response to stress’, ‘response to biotic stimulus’, ‘immune system process’, etc. Further investigation based on analysis of domains, enzyme classification, pathways enrichment, transcription factors (TFs), interactions with microRNAs (miRNAs), and real-time quantitative PCR of lncRNAs and co-expressing CDS pairs suggested their involvement in modulation of basal and specific defense responses such as: Ca2+-dependent signaling, cell wall reinforcement, reactive oxygen species metabolism, pathogenesis related proteins accumulation, phytohormonal signal transduction, and secondary metabolism. Conclusions Overall, the identified lncRNAs provide insights into the underlying intricacy of grapevine transcriptional reprogramming/post-transcriptional regulation to delay or seize the living cell-dependent pathogen growth. Therefore, in addition to defense-responsive genes such as TFs, the identified lncRNAs can be further examined and leveraged to candidates for biotechnological improvement/breeding to enhance fungal stress resistance in this susceptible fruit crop of economic and nutritional importance.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ammar Zaghlool ◽  
Adnan Niazi ◽  
Åsa K. Björklund ◽  
Jakub Orzechowski Westholm ◽  
Adam Ameur ◽  
...  

AbstractTranscriptome analysis has mainly relied on analyzing RNA sequencing data from whole cells, overlooking the impact of subcellular RNA localization and its influence on our understanding of gene function, and interpretation of gene expression signatures in cells. Here, we separated cytosolic and nuclear RNA from human fetal and adult brain samples and performed a comprehensive analysis of cytosolic and nuclear transcriptomes. There are significant differences in RNA expression for protein-coding and lncRNA genes between cytosol and nucleus. We show that transcripts encoding the nuclear-encoded mitochondrial proteins are significantly enriched in the cytosol compared to the rest of protein-coding genes. Differential expression analysis between fetal and adult frontal cortex show that results obtained from the cytosolic RNA differ from results using nuclear RNA both at the level of transcript types and the number of differentially expressed genes. Our data provide a resource for the subcellular localization of thousands of RNA transcripts in the human brain and highlight differences in using the cytosolic or the nuclear transcriptomes for expression analysis.


2021 ◽  
Vol 22 (6) ◽  
pp. 3151 ◽  
Author(s):  
Roberto Piergentili ◽  
Simona Zaami ◽  
Anna Franca Cavaliere ◽  
Fabrizio Signore ◽  
Giovanni Scambia ◽  
...  

Endometrial cancer (EC) has been classified over the years, for prognostic and therapeutic purposes. In recent years, classification systems have been emerging not only based on EC clinical and pathological characteristics but also on its genetic and epigenetic features. Noncoding RNAs (ncRNAs) are emerging as promising markers in several cancer types, including EC, for which their prognostic value is currently under investigation and will likely integrate the present prognostic tools based on protein coding genes. This review aims to underline the importance of the genetic and epigenetic events in the EC tumorigenesis, by expounding upon the prognostic role of ncRNAs.


BMC Genomics ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Amy Webb ◽  
Audrey C. Papp ◽  
Amanda Curtis ◽  
Leslie C. Newman ◽  
Maciej Pietrzak ◽  
...  

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 692
Author(s):  
Sweta Talyan ◽  
Samantha Filipów ◽  
Michael Ignarski ◽  
Magdalena Smieszek ◽  
He Chen ◽  
...  

Diseases of the renal filtration unit—the glomerulus—are the most common cause of chronic kidney disease. Podocytes are the pivotal cell type for the function of this filter and focal-segmental glomerulosclerosis (FSGS) is a classic example of a podocytopathy leading to proteinuria and glomerular scarring. Currently, no targeted treatment of FSGS is available. This lack of therapeutic strategies is explained by a limited understanding of the defects in podocyte cell biology leading to FSGS. To date, most studies in the field have focused on protein-coding genes and their gene products. However, more than 80% of all transcripts produced by mammalian cells are actually non-coding. Here, long non-coding RNAs (lncRNAs) are a relatively novel class of transcripts and have not been systematically studied in FSGS to date. The appropriate tools to facilitate lncRNA research for the renal scientific community are urgently required due to a row of challenges compared to classical analysis pipelines optimized for coding RNA expression analysis. Here, we present the bioinformatic pipeline CALINCA as a solution for this problem. CALINCA automatically analyzes datasets from murine FSGS models and quantifies both annotated and de novo assembled lncRNAs. In addition, the tool provides in-depth information on podocyte specificity of these lncRNAs, as well as evolutionary conservation and expression in human datasets making this pipeline a crucial basis to lncRNA studies in FSGS.


eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Andrew R Bassett ◽  
Asifa Akhtar ◽  
Denise P Barlow ◽  
Adrian P Bird ◽  
Neil Brockdorff ◽  
...  

Although a small number of the vast array of animal long non-coding RNAs (lncRNAs) have known effects on cellular processes examined in vitro, the extent of their contributions to normal cell processes throughout development, differentiation and disease for the most part remains less clear. Phenotypes arising from deletion of an entire genomic locus cannot be unequivocally attributed either to the loss of the lncRNA per se or to the associated loss of other overlapping DNA regulatory elements. The distinction between cis- or trans-effects is also often problematic. We discuss the advantages and challenges associated with the current techniques for studying the in vivo function of lncRNAs in the light of different models of lncRNA molecular mechanism, and reflect on the design of experiments to mutate lncRNA loci. These considerations should assist in the further investigation of these transcriptional products of the genome.


2021 ◽  
Vol 34 (Supplement_1) ◽  
Author(s):  
Siyuan Luan ◽  
Yushang Yang ◽  
Shouyue Zhang ◽  
Xiaoxi Zeng ◽  
Xin Xiao ◽  
...  

Abstract   Long non-coding RNAs (lncRNAs), a type of transcriptional products with more than 200 nucleotides in length, have been less characterized compared to protein-coding RNAs so far. However, it is increasingly evident that lncRNAs are key players involved in multiple genetic and epigenetic activities during the carcinogenesis of neoplastic diseases. Currently, accumulating data have pointed out the close connection between lncRNAs and esophageal carcinoma (EC), shedding light on further unravelling the complexity of lncRNAs and EC. Methods In this review, we thoroughly collect the evidence regarding original studies on EC-related lncRNAs by searching in MEDLINE/PubMed, Embase and WOS/SCI. We especially focus on summarizing EC-related lncRNAs based upon more updated evidence, and further discuss their different features from various perspectives, including regulatory mechanisms, functional roles in cancer hallmarks, as well as potential diagnostic and therapeutic applications, which would together reveal the complexity of lncRNAs and EC for potential clinical applications. Results We discuss over thirty EC-related lncRNAs in total, most of which function as oncogenes that promote cancer development, while the others function as tumor suppressors. Regulatory mechanisms included sponging miRNAs, direct interaction with proteins, and exosome visicle-based intercellular communication. Based upon these modes of actions, lncRNAs play multiple roles in cancer hallmarks such as uncontrolled cell growth, evasion of programmed cell death, invasion and metastasis. Moreover, lncRNAs packaged in exosomes have unique potency to serve as diagnostic biomarkers; some lncRNAs show great potential to predict patients' chemical resistance and may be crucial targets to improve chemoradiotherapy and targeted therapy. Conclusion Over the past few years, the research of EC-related lncRNAs maintain obviously rapid development, yet further exploration of exact mechanisms and clinical applications that lncRNAs can offer need to be done. Indeed, LncRNAs hold the promise of being applied in multiple clinical scenarios, especially early diagnosis of EC, improvement of sensitivity to chemotherapy/radiotherapy, and development of small-molecule targeted drugs.


2018 ◽  
Vol 4 (4) ◽  
pp. 40 ◽  
Author(s):  
Carolyn Klinge

Non-coding RNAs (ncRNAs) are regulators of intracellular and intercellular signaling in breast cancer. ncRNAs modulate intracellular signaling to control diverse cellular processes, including levels and activity of estrogen receptor α (ERα), proliferation, invasion, migration, apoptosis, and stemness. In addition, ncRNAs can be packaged into exosomes to provide intercellular communication by the transmission of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) to cells locally or systemically. This review provides an overview of the biogenesis and roles of ncRNAs: small nucleolar RNA (snRNA), circular RNAs (circRNAs), PIWI-interacting RNAs (piRNAs), miRNAs, and lncRNAs in breast cancer. Since more is known about the miRNAs and lncRNAs that are expressed in breast tumors, their established targets as oncogenic drivers and tumor suppressors will be reviewed. The focus is on miRNAs and lncRNAs identified in breast tumors, since a number of ncRNAs identified in breast cancer cells are not dysregulated in breast tumors. The identity and putative function of selected lncRNAs increased: nuclear paraspeckle assembly transcript 1 (NEAT1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), steroid receptor RNA activator 1 (SRA1), colon cancer associated transcript 2 (CCAT2), colorectal neoplasia differentially expressed (CRNDE), myocardial infarction associated transcript (MIAT), and long intergenic non-protein coding RNA, Regulator of Reprogramming (LINC-ROR); and decreased levels of maternally-expressed 3 (MEG3) in breast tumors have been observed as well. miRNAs and lncRNAs are considered targets of therapeutic intervention in breast cancer, but further work is needed to bring the promise of regulating their activities to clinical use.


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