0000000000635145
AUTHOR
Lola De Miguel-jiménez
Genome-wide studies of mRNA synthesis and degradation in eukaryotes
In recent years, the use of genome-wide technologies has revolutionized the study of eukaryotic transcription producing results for thousands of genes at every step of mRNA life. The statistical analyses of the results for a single condition, different conditions, different transcription stages, or even between different techniques, is outlining a totally new landscape of the eukaryotic transcription process. Although most studies have been conducted in the yeast Saccharomyces cerevisiae as a model cell, others have also focused on higher eukaryotes, which can also be comparatively analyzed. The picture which emerges is that transcription is a more variable process than initially suspected,…
Chromatin-dependent regulation of RNA polymerases II and III activity throughout the transcription cycle
The particular behaviour of eukaryotic RNA polymerases along different gene regions and amongst distinct gene functional groups is not totally understood. To cast light onto the alternative active or backtracking states of RNA polymerase II, we have quantitatively mapped active RNA polymerases at a high resolution following a new biotin-based genomic run-on (BioGRO) technique. Compared with conventional profiling with chromatin immunoprecipitation, the analysis of the BioGRO profiles in Saccharomyces cerevisiae shows that RNA polymerase II has unique activity profiles at both gene ends, which are highly dependent on positioned nucleosomes. This is the first demonstration of the in vivo infl…
The mRNA degradation factor Xrn1 regulates transcription elongation in parallel to Ccr4
Abstract Co-transcriptional imprinting of mRNA by Rpb4 and Rpb7 subunits of RNA polymerase II (RNAPII) and by the Ccr4–Not complex conditions its post-transcriptional fate. In turn, mRNA degradation factors like Xrn1 are able to influence RNAPII-dependent transcription, making a feedback loop that contributes to mRNA homeostasis. In this work, we have used repressible yeast GAL genes to perform accurate measurements of transcription and mRNA degradation in a set of mutants. This genetic analysis uncovered a link from mRNA decay to transcription elongation. We combined this experimental approach with computational multi-agent modelling and tested different possibilities of Xrn1 and Ccr4 acti…