Friday, June 24, 2022

[DMANET] Virtual seminar of Cynthia Sharma - mechanisms/functions of small RNAs in bacteria, 4th of July - 4pm CET

Dear colleagues,


In the framework of the small non-coding RNA bioinformatics club (https://smallrna-bioinformatics.eu/), we are happy to share with you the seminar of Cynthia Sharma related to mechanisms/functions of small RNAs in bacteria.

Caution: the seminar will not be recorded this time.

More information here and below (including future seminars): https://smallrna-bioinformatics.eu/Pages/Seminars/S22_07.aspx

Start Monday July 4th at 4pm (CET, Berlin/Paris)

(3 pm London/Lisbon, 10am New-York, 7am San Francisco, 5pm Tel Aviv)

Link to the Zoom conference: https://univ-grenoble-alpes-fr.zoom.us/j/93609306988?pwd=SWdvS1RPc0oxbDRRai9GUmpKN0t0dz09
Link to the YouTube stream: https://www.youtube.com/watch?v=VYIKBJq_coM


Main Speaker: Cynthia Sharma, Professor, Institute of Molecular Infection Biology (IMIB), University of Würzburg, Germany (Link<http://www.imib-wuerzburg.de/research/sharma/research/>)

Title: Regulatory RNAs in pathogenic Epsilonproteobacteria


Abstract:

Non-coding RNAs and RNA-protein (RNP) complexes play central roles in diverse physiological processes in all kingdoms of life. Research in our lab focuses on RNA-based processes in the two pathogenic Epsilonproteobacteria Helicobacter pylori, the cuasative agent of gastric cancer, and the related food-borne pathogen Campylobacter jejuni. We are especially interested in the roles of small, regulatory RNAs (sRNAs) and RNPs in virulence control as well as novel mechanisms of gene regulation. For example, we have discovered new connections between so-called phase-variation at length variable DNA repeats and post-transcriptional regulation. I will present our work on sRNAs from H. pylori and C. jejuni that target variable G-repeats and regulate genes involved in host colonization as well as antibiotic sensitivity. Moreover, we recently identified a sRNA that is itself regulated by a phase-variable repeat and acts as a central regulator of the major virulence factors of H. pylori.

Short session speaker (8 minutes long): Fabian König

Title: A 3´UTR-derived, processed small RNA modulates flagellar biogenesis by repression of the anti-sigma factor FlgM in Campylobacter jejuni

Abstract:
In Campylobacter jejuni, as for many pathogens, flagella are a crucial virulence factor, enabling traversal through the viscous mucus layer of the human intestine. Flagellar biogenesis is known to involve hierarchical transcriptional control of each component, with class I genes transcribed from sigma-70-dependent promoters, and class II and class III genes transcribed with the help of alternative sigma factors, RpoN and FliA, respectively. In contrast to transcriptional control, less is known about post-transcriptional regulation of flagellar biosynthesis cascades by small regulatory RNAs (sRNAs). Here, we have characterized a conserved Campylobacter sRNA, CJnc230, encoded downstream of the RpoN-dependent flagellar hook structural protein FlgE, and found that three ribonucleases are involved in sRNA maturation. RNase III cleaves off the sRNA from the flgE mRNA, while RNase Y and PNPase process CJnc230 at its 3´ end. We identified a regulator of flagella-flagella interactions as well as the anti-sigma-28 factor FlgM as targets of CJnc230 repression. CJnc230 overexpression led to de-repression of FliA and subsequent upregulation of class III flagellar genes such as the major flagellin flaA, culminating in an increase in motility and flagellar length. Overexpression of the FliA-dependent sRNA CJnc170 instead led to reduced motility suggesting sRNA-mediated regulation of C. jejuni flagellar biosynthesis through balancing of the hierarchically expressed components.

The club propose seminars every two months. Abstracts and links for the seminars are available here: https://smallrna-bioinformatics.eu/Pages/Seminars/Seminars.aspx

Tweet for easy re-transmission: https://twitter.com/Laurent_Guyon/status/1540352879780892672
YouTube channel (most of the seminars are then shared through this channel, but not this one): https://www.youtube.com/channel/UCTiHtqOKzneeqIqauQMgx3A

Seminars are given at 4pm CET, except in rare cases.
- 4 July 2022 - Cynthia Sharma - mechanisms/functions of small RNAs in bacteria
- 10 October 2022 (updated) - Marc Friedländer - miRNA-target interactions in single cells
- 7 November 2022 - Amy Buck - Dr Buck is working in the field of microRNA-virus interactions

'hope to see you virtually in these seminars,
Laurent Guyon, on behalf of all the organizers (Rolf Backofen, Ana Eulálio, Bastian Fromm, Laurent Guyon, Andreas Keller, Marie-France Sagot)

____________________________
Laurent GUYON, PhD, HDR - Bioinformatics
CEA IRIG (Interdisciplinary Research Institute of Grenoble<http://www.cea.fr/drf/IRIG/english/Pages/Presentation.aspx>)
BioHealth Department - BCI (Biology of Cancer and Infection laboratory<http://www.bci-lab.fr/en>)
UMR 1292 CEA/Inserm/Université Grenoble Alpes

CEA Grenoble - Bât C3 - Bureau 224
17 rue des Martyrs - 38054 GRENOBLE Cedex 9 - France

Tél : (+33)4.38.78.04.53 - Fax : (+33)4 38 78 50 58
Email : laurent.guyon@cea.fr<mailto:laurent.guyon@cea.fr> - http://laurent.guyon.phd.free.fr/

Interested by small non-coding RNA bioinformatics? Join the club! https://smallrna-bioinformatics.eu/

Special issue on small non-coding RNA bioinformatics, submit before the 15th of October (updated - contact me if you need delay):
https://www.mdpi.com/journal/genes/special_issues/Small_RNA_Bioinformatics

Happy to share miRViz (free to use website to analyze your microRNA datasets): http://mirviz.prabi.fr/
Article: https://doi.org/10.1093/nar/gkaa259
Messages of the paper: https://twitter.com/Laurent_Guyon/status/1255487510563651586


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