bioRxiv Science⌕ Search

Biology subjects

Onoguchi, M.

Publications and source records attributed to Onoguchi, M..

4 recordsLinked to original sources

Alignment-free discovery of conserved RNA structures in the human genome

Many functional RNAs were first found as conserved RNA structures, and their roles in gene regulation were identified later. In humans and other vertebrates, imperfect genome alignments have hindered the discovery of such structures. Here we present RLMHelix, which selects candidate conserved RNA structures from single sequences before any alignment by scoring helices supported by language-model dependencies and thermodynamics. Through distillation, RLMHelix rapidly scans the transcribed human genome and ranks known RNAs higher than conventional thermodynamic scanning. Two-thirds of 15,821 candidates are new to four earlier genome-wide screens, yet agree with in-cell probing, and over half retain structural signal in homologues. In eCLIP data and in exploratory pull-downs, higher RLMHelix scores were associated with more binding by double-stranded RNA-binding proteins. By linking candidates to their binding proteins, RLMHelix yields testable functional hypotheses and illuminates a path from unrecognized human RNA structures to RNA biology and therapeutic targets.

bioinformatics↗

Binding patterns of RNA binding proteins to repeat-derived RNA sequences reveal putative functional RNA elements

Recent reports have revealed that repeat-derived sequences embedded in introns or long noncoding RNAs (lncRNAs) are targets of RNA binding proteins (RBPs) and contribute to biological processes such as RNA splicing or transcriptional regulation. These findings suggest that repeat-derived RNAs are important as scaffolds of RBPs and functional elements. However, the overall functional sequences of the repeat-derived RNAs are not fully understood. Here, we show the putative functional repeat-derived RNAs by analyzing the binding patterns of RBPs based on ENCODE eCLIP data. We mapped all eCLIP reads to repeat sequences and observed that 10.75 % and 7.04 % of reads on average were enriched (at least 2-fold over control) in the repeats in K562 and HepG2 cells, respectively. Using these data, we predicted functional RNA elements on the sense and antisense strands of long interspersed element 1 (LINE1) sequences. Furthermore, we found several new sets of RBPs on fragments derived from other transposable element (TE) families. Some of these fragments show specific and stable secondary structures and are found to be inserted into the introns of genes or lncRNAs. These results suggest that the repeat-derived RNA sequences are strong candidates for the functional RNA elements of endogenous noncoding RNAs.

genomics↗

Association analysis of repetitive elements and R-loop formation across species

Genomes are known to have a large number of repetitive elements. Emerging evidence suggests that these non-coding elements may play an important regulatory role. However, few studies have investigated the effect of repetitive elements on R-loop formation. In this study, we found different repetitive elements related to R-loop formation in various species. By controlling length and genomic distributions, we observed that satellites, long interspersed nuclear elements (LINEs), and DNAs were each specifically enriched for R-loops in humans, fruit flies, and Arabidopsis thaliana, respectively. R-loops also tended to arise in regions of low-complexity or simple repeats across species. We also found that the repetitive elements associated with R-loop formation differ according to developmental stage. For instance, LINEs and long terminal repeats (LTRs) are more likely to contain R-loops in embryos (fruit fly) and then turn out to be low-complexity and simple repeats in post-developmental S2 cells. Our results indicate that repetitive elements may have species-specific or development-specific regulatory effects on R-loop formation. This work advances our understanding of repetitive elements and R-loop biology.

genomics↗

The novel lncRNA lnc-NR2F1 is pro-neurogenic and mutated in human neurodevelopmental disorders

Long noncoding RNAs (lncRNAs) have been shown to act as important cell biological regulators including cell fate decisions but are often ignored in human genetics. Combining differential lncRNA expression during neuronal lineage induction with copy number variation morbidity maps of a cohort of children with autism spectrum disorder/intellectual disability versus healthy controls revealed focal genomic mutations affecting several lncRNA candidate loci. Here we find that a t(5:12) chromosomal translocation in a family manifesting neurodevelopmental symptoms disrupts specifically lnc-NR2F1. We further show that lnc-NR2F1 is an evolutionarily conserved lncRNA functionally enhances induced neuronal cell maturation and directly occupies and regulates transcription of neuronal genes including autism-associated genes. Thus, integrating human genetics and functional testing in neuronal lineage induction is a promising approach for discovering candidate lncRNAs involved in neurodevelopmental diseases.

neuroscience↗