Dts-seq: a simple method of library preparation for a highly reproducible characterization of the tRNA epitranscriptome by deep sequencing
Ontology highlight
ABSTRACT: High-throughput sequencing of cellular tRNAs is severely hindered by the presence of base modifications. These modifications impair the reverse transcription (RT) enzyme and prevent a large fraction of transcripts to be converted into cDNA in conventional sequence library preparation. Recent attempts to circumvent this issue made use of enzymatic treatments to remove methyl groups (Cozen et al. 2015; Zeng et al. 2015). This approach is, however, not fully satisfactory because it can clear the way to the RT enzyme for only a fraction of all tRNAs. Another approach takes advantage of the interference of modifications with RT enzymes to detect and identify them in fragmented RNA transcripts (Hauenschild et al. 2015; Helm and Motorin 2017; Schwartz and Motorin 2017). In line with this second approach, we present results of an alternate method that is simpler and fully adapted to the direct characterization and quantification of mature tRNA transcripts. An analysis of the obtained read coverages enables to generate highly reproductible patterns of termination signals that can be used to assess the modification state of all tRNAs.
ORGANISM(S): Escherichia coli str. K-12 substr. MG1655
Project description:Coleoid cephalopods possess a highly complex nervous system and a rich behavioral repertoire that is unique within the invertebrates and is comparable to – but evolved independently from – the vertebrates (Shigeno et al. 2018). To explain this complexity, previous studies have implicated a unusually high level of mRNA editing in transcripts expressed in both the octopus and squid nervous system (Albertin et al. 2015; Alon et al. 2015; Liscovitch-Brauer et al. 2017). We have sequenced RNA across 18 tissues from the octopus O. vulgaris, and analyzed the extent of mRNA isoform usage as well as the expression of microRNAs in the nervous system in comparison to non-neuronal tissues.
Project description:RNA-sequencing data from human iPSC PGP1 cells (n=4) differentiated into mesoderm (day-2) (n=4) or cardiomyocytes (days 25-30) (n=4) through modulation of Wnt/β-catenin signaling as previously described (Cohn et al., 2019; Hinson et al., 2017; Hinson et al., 2015; Lian et al., 2012).
Project description:Genomic DNA from 180 Col/Bur F2 individuals, and 186 taf4b/Bur F2 individuals, was extracted by CTAB and used to generate sequencing libraries as previously described (Ziolkowski et al, 2017 Genes & Dev). Sequencing data was analysed to identify crossovers using the TIGER pipeline as previously described (Rowan et al, 2015 G3 (Bethesda); Yelina et al, 2015 Genes & Dev).
Project description:Genomic DNA from 192 recq4a recq4b and 192 HEI10 recq4a recq4b Col x Ler F2 individuals was extracted using CTAB and used to generate sequencing libraries as described (Ziolkowski et al, 2017 Genes & Dev). Sequencing data was analysed to identify crossovers as previously reported, using the TIGER pipeline (Rowan et al, 2015 G3 (Bethesda); Yelina et al, 2015 Genes & Dev).
Project description:Lewy body (LB) pathology and loss of dopaminergic neurons are imprints of Parkinson’s disease (PD). LBs are mainly comprised of alpha-Synuclein (Dijkstra et al., 2014). Strolling detection of LBs in brain regions contribute to progressive construct of PD pathology to which molecular mechanisms are not clear (H. Braak & Del Tredici, 2017). Two key facets of LB formation are protein aggregation via misfolding and transmission of misfoldled proteins to various brain regions, eventually causing neuronal death (Goedert, Spillantini, Del Tredici, & Braak, 2013; Pacelli et al., 2015). Misfolding requires alterations in intracellular physiology (Carbone, Costa, Provensi, Mannaioni, & Masi, 2017; Funes et al., 2014; Guzman et al., 2018; Pacelli et al., 2015) and detection of misfolded proteins in exosomes confirms exosomatic transmission (Ngolab et al., 2017). High levels of neurotropic-factors (Brockmann et al., 2017) and changes in bioenergetics are found in PD patients, these can bring physiological alterations (Smith et al., 2018). En masse, these evidences and hipocampal association with synucleopathies (Flores-Cuadrado, Ubeda-Bañon, Saiz-Sanchez, de la Rosa-Prieto, & Martinez-Marcos, 2016) allowed us to probe other volunerable PD proteins in cell-lysate and exosomal proteomes of bFGF treated hippocampal neurons. Using WPCNA we developed co-expression modules and spotted many PD related proteins; which can act as precursors during diseased or onset stage.
Project description:To associate the amount of tRNAs with codon usage, we perform hydro-tRNA sequencing (Gogakos et al. 2017) and quantify tRNA expression in HEK293 and HeLa cells.
Project description:CD47 is a transmembrane glycoprotein that is ubiquitously expressed in different organs and tissues (Barclay and Van den Berg 2014; Liu, et al. 2017). In the human immune system, CD47 interacts with some integrins, two counter-receptor signal regulator protein (SIRP) family members, and the secreted thrombospondin-1 (TSP1) (Barclay and Van den Berg 2014; Gao, et al. 2016; Kaur, et al. 2013; Oldenborg, et al. 2000). CD47 has two established roles in the immune system. The CD47-SIRPα interaction was identified as a critical innate immune checkpoint, which delivers an antiphagocytic signal to macrophages and inhibits neutrophil cytotoxicity (Martínez- Sanz, et al. 2021). Its interaction with inhibitory SIRPα is a physiological anti-phagocytic “don’t eat me” signal on circulating red blood cells that is co-opted by cancer cells (Matlung, et al. 2017). Many malignant cells overexpress CD47 (Betancur, et al. 2017; Chao, et al. 2011; Jaiswal, et al. 2009; Majeti, et al. 2009; Oronsky, et al. 2020; Petrova, et al. 2017). CD47/SIRPα-targeted therapeutics have been developed to overcome this immune checkpoint for cancer treatment (Kaur, et al. 2020; Matlung, et al. 2017). Secondly, engagement of CD47 on T cells by TSP1 regulates their differentiation and survival (Grimbert, et al. 2006; Lamy, et al. 2007) and inhibits T cell receptor signaling and antigen presentation by dendritic cells (DCs) (Kaur, et al. 2014; Li, et al. 2002; Liu, et al. 2015; Miller, et al. 2013; Soto-Pantoja, et al. 2014; Weng, et al. 2014). TSP1/CD47 signaling has similar inhibitory functions to limit NK cell activation (Kim, et al. 2008; Nath, et al. 2018; Nath, et al. 2019; Schwartz, et al. 2019) and IL1β production by macrophages (Stein, et al. 2016). CD47 is therefore a checkpoint that regulates both innate and adaptive immunity. The recent understanding of CD47 antagonism associated with increased antigen presentation by DCs (Liu, et al. 2016) and natural killer cell cytotoxicity (Nath, et al. 2019) contributes to the heightened interest in CD47 as a therapeutic target (Kaur, et al. 2020).
Project description:The lysine 23 of histone H3 (H3K23me2) positively correlates with H3K9me3 and H3K27me3, marks enriched in heterochromatic regions (Ho, J.W. et al., 2014; Garrigues, J.M. et al., 2015; Liu, T. et al., 2015), and negatively correlates with H3K36me2/3 and H3K23/27ac, modifications enriched in actively transcribed regions. Similarly to the reported distribution of H3K9me3 (Ho, J.W. et al., 2014; Garrigues, J.M. et al., 2015), H3K23me2 is enriched on autosomal arms and is depleted from the central regions of the autosomes and from most of the lenght of the X chromosome.
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Project description:We measured abundances of tRNAs by means of hydro-tRNA-seq (Gogakos et al., 2017), a method based on partial alkaline RNA hydrolysis that generates fragments suitable for sequencing, in the genome-reduced bacterium Mycoplasma pneumoniae.