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SUMMARY:Evidence for pervasive transcription in trypanosomes - Dr Antonio 
 Estevez (Instituto de Parasitología y Biomedicina 'López-Neyra’\, IPBL
 N-CSIC\, Granada\, Spain)
DTSTART:20221026T150000Z
DTEND:20221026T160000Z
UID:TALK180503@talks.cam.ac.uk
CONTACT:Anna Protasio
DESCRIPTION:In-depth analysis of the transcriptomes of several model organ
 isms has revealed that genomes are pervasively transcribed\, giving rise t
 o an abundance of non-canonical and mainly antisense RNA-polymerase II-
 derived transcripts that are produced from almost any genomic context. The
 se RNAs are degraded by surveillance mechanisms\, but the repertoire of ce
 llular factors that control the fate of these non-productive transcripts 
 is still incomplete. Trypanosomes are single-celled eukaryotes that sho
 w constitutive RNA polymerase II transcription and have a very unusual gen
 ome architecture. In these organisms\, the initiation and termination of t
 ranscription occur at a limited number of sites per chromosome\, and the r
 egulation of gene expression is exerted mainly at the post-transcriptional
  level. It is not known whether pervasive transcription exists in organism
 s with unregulated RNA polymerase II activity\, and which factors could be
  involved in the process. In this work\, we show that depletion of RBP33\,
  an RNA-binding protein apparently unique in trypanosomatids\, results in 
 the overexpression of up to 40% of all annotated genes in the genome\, wit
 h a marked accumulation of sense and antisense transcripts derived from si
 lenced regions. RBP33 loss does not result in a significant increase in ch
 romatin accessibility\, as judged by ATAC-seq analysis. Finally\, we have 
 found that transcripts that increase in abundance upon RBP33 knockdown are
  significantly more stable in RBP33-depleted trypanosomes\, and that the e
 xosome complex is responsible for their degradation. Our results provide s
 trong evidence that RBP33 dampens non-productive transcription in trypanos
 omes.\n\nWe encourage in person attendance but the talk will also be strea
 med via "zoom":https://zoom.us/j/95353754098?pwd=UEl0WnlwNndrZnFNQnJNVDg4U
 HlLQT09
LOCATION:Seminar Room\, Tennis Court Road\, Dept of Pathology.
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