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Louloupi, A.

Publications and source records attributed to Louloupi, A..

3 recordsLinked to original sources

SPLICE-q: a Python tool for genome-wide quantification of splicing efficiency

BackgroundIntrons are generally removed from primary transcripts to form mature RNA molecules in a post-transcriptional process called splicing. An efficient splicing of primary transcripts is an essential step in gene expression and its misregulation is related to numerous human diseases. Thus, to better understand the dynamics of this process and the perturbations that might be caused by aberrant transcript processing it is important to quantify splicing efficiency. ResultsHere, we introduce SPLICE-q, a fast and user-friendly Python tool for genome-wide SPLICing Efficiency quantification. It supports studies focusing on the implications of splicing efficiency in transcript processing dynamics. SPLICE-q uses aligned reads from strand-specific RNA-seq to quantify splicing efficiency for each intron individually and allows the user to select different levels of restrictiveness concerning the introns overlap with other genomic elements such as exons of other genes. We applied SPLICE-q to globally assess the dynamics of intron excision in yeast and human nascent RNA-seq. We also show its application using total RNA-seq from a patient-matched prostate cancer sample. ConclusionsOur analyses illustrate that SPLICE-q is suitable to detect a progressive increase of splicing efficiency throughout a time course of nascent RNA-seq and it might be useful when it comes to understanding cancer progression beyond mere gene expression levels. SPLICE-q is available at: https://github.com/vrmelo/SPLICE-q

bioinformatics↗

Transient N-6-methyladensosine Transcriptome sequencing reveals a regulatory role of m6A in splicing efficiency

Splicing efficiency varies among transcripts, and tight control of splicing kinetics is crucial for coordinated gene expression. N-6-methyladenosine (m6A) is the most abundant RNA modification and is involved in regulation of RNA biogenesis and function. The impact of m6A on the regulation of RNA splicing kinetics has not been investigated. Here, we provide the first time-resolved high-resolution assessment of m6A on nascent RNA transcripts and unveil its importance for the control of RNA splicing kinetics. We identify that early co-transcriptional m6A deposition near splice junctions promotes fast splicing, while m6A modification of introns is associated with long, slowly processed introns and alternative splicing events. In conclusion, by directly comparing the processing dynamics of individual transcripts in the methylated versus unmethylated state on a transcriptome-wide scale we show that early m6A deposition marks transcripts for a fast-track processing.

molecular biology↗

Microprocessor dynamics shows co- and post-transcriptional processingof pri-miRNAs

miRNAs are small regulatory RNAs involved in the regulation of translation of target transcripts. miRNA biogenesis is a multi-step process starting with the cleavage of the primary miRNA transcript in the nucleus by the Microprocessor complex. Endogenous processing of pri-miRNAs is challenging to study and the in vivo kinetics of this process is not known. Here, we present a method for determining the processing kinetics of pri-miRNAs within intact cells over time using a pulse-chase approach to obtain nascent RNA within a 1-hour window after labeling with bromouridine. We show, that pri-miRNAs exhibit different processing kinetics ranging from fast over intermediate to slow processing and provide evidence that pri-miRNA processing can occur both co-transcriptionally and post-transcriptionally.

molecular biology↗