Biology subjects

Wessels, H.-H.

Publications and source records attributed to Wessels, H.-H..

4 recordsLinked to original sources

bioRxiv2018

Global identification of functional microRNA::mRNA interactions in Drosophila

MicroRNAs (miRNAs) are key mediators of post-transcriptional gene expression silencing. Although Drosophila has been of critical importance for miRNA discovery, biogenesis and function, there has been no comprehensive experimental annotation of functional miRNA target sites. To close this gap, we generated the first in vivo map of miRNA::mRNA interactions in Drosophila melanogaster, making use of crosslinked nucleotides in Argonaute (AGO) crosslinking and immunoprecipitation (CLIP) experiments that enable an unambiguous assignment of miRNAs to AGO binding sites at much higher signal-to-noise ratio than computational predictions alone.\n\nAbsolute quantification of cellular miRNA levels showed the miRNA pool in Drosophila cell lines to be more diverse than previously reported. Benchmarking two different CLIP approaches, we identified a similar predictive potential to unambiguously assign thousands of miRNA::mRNA pairs from AGO1 interaction data at unprecedented depth. Quantitative RNA-Seq and subcodon-resolution ribosomal footprinting data upon AGO1 depletion enabled the determination of miRNA-mediated effects on target expression and translation. We thus provide the first comprehensive resource of miRNA target sites as well as their quantitative functional impact in Drosophila.

systems biology↗

bioRxiv2018

Purification of Cross-linked RNA-Protein Complexes by Phenol-Toluol Extraction

Recent methodological advances allowed the identification of an increasing number of RNA-binding proteins (RBPs) and their RNA-binding sites. Most of those methods rely, however, on capturing proteins associated to polyadenylated RNAs which neglects RBPs bound to non-adenylate RNA classes (tRNA, rRNA, pre-mRNA) as well as the vast majority of species that lack poly-A tails in their mRNAs (including all archea and bacteria). To overcome these limitations, we have developed a novel protocol, Phenol Toluol extraction (PTex), that does not rely on a specific RNA sequence or motif for isolation of cross-linked ribonucleoproteins (RNPs), but rather purifies them based entirely on their physicochemical properties. PTex captures RBPs that bind to RNA as short as 30 nt, RNPs directly from animal tissue and can be used to simplify complex workflows such as PAR-CLIP. Finally, we provide a first global RNA-bound proteome of human HEK293 cells and Salmonella Typhimurium as a bacterial species.

molecular biology↗

bioRxiv2018

Deciphering human ribonucleoprotein regulatory networks

RNA-binding proteins (RBPs) control and coordinate each stage in the life cycle of RNAs. Although in vivo binding sites of RBPs can now be determined genome-wide, most studies typically focused on individual RBPs. Here, we examined a large compendium of 114 high-quality transcriptome-wide in vivo RBP-RNA cross-linking interaction datasets generated by the same protocol in the same cell line and representing 64 distinct RBPs. Comparative analysis of categories of target RNA binding preference, sequence preference, and transcript region specificity was performed, and identified potential posttranscriptional regulatory modules, i.e. specific combinations of RBPs that bind to specific sets of RNAs and targeted regions. These regulatory modules encoded functionally related proteins and exhibited distinct differences in RNA metabolism, expression variance, as well as subcellular localization. This integrative investigation of experimental RBP-RNA interaction evidence and RBP regulatory function in a human cell line will be a valuable resource for understanding the complexity of post-transcriptional regulation.

genomics↗

bioRxiv2017

omniCLIP: Bayesian identification of protein-RNA interactions from CLIP-Seq data

High-throughput immunoprecipitation methods to analyze RNA binding protein - RNA in-teractions and modifications have great potential to further the understanding of post-tran-scriptional gene regulation. Due to the differences between individual approaches, each of a diverse number of computational methods can typically be applied to only one specific se-quencing protocol. Here, we present a Bayesian model called omniCLIP that can be applied to data from all protocols to detect regulatory elements in RNAs. omniCLIP greatly sim-plifies the data analysis, increases the reliability of results and paves the way for integrative studies based on data from different sources.

bioinformatics↗