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Archives of Industrial Biotechnology | Volume 2
May 14-15, 2018 | Montreal, Canada
World Yeast Congress
T
he chemotherapeutic agent Hydroxyurea (HU) inhibits
the ribonucleotide reductase preventing the synthesis
of dNTPs. Consequently, DNA replication is inhibited and
cells arrest in G1/early S-phase of the cell cycle. Additionally,
yeast exposed to the natural pheromone α-factor arrest cell
division in G1. Cell growth hinges on the tightly regulated
processes of ribosome biogenesis and rRNA synthesis. Thus,
expression of rRNA genes and rRNA processingwere analyzed
in cell cycle arrested cells by both the chemotherapeutic
agent HU and the pheromone α-factor. Chromatin
endogenous cleavage, chromatin immuno-precipitation,
chromatin spreading and Northern blotting were employed
to investigate the effect of HU on the expression of rRNA
genes and rRNA synthesis. The results indicate that in yeast
arrested by HU the overall number of active promoters
remains unchanged, and that rRNA genes chromatin stay
poised for transcription. However, distribution of RNAPI on
individual rRNA gene and rRNA processing are disturbed,
lowering rRNA synthesis. Conversely, in α-factor arrested
cells rRNA transcription was not affected. These results
point out a hitherto unnoticed cellular response to HU that
might participate in the inhibition of cell division. NSERC
and Ministère des Relations Internationales du Québec (to
AC), Bavarian State Chancellery (Bayerisch-Franzosisches
Hochschulzentrum, to JG).
Speaker Biography
Alexia Muguet has a master in marine ecology from the Université Pierre et Marie Curie
- Paris VI (France) (2014) and a master in microbiology from the Université de Bretagne
Occidentale (France) (2015). She previously worked on microalgae ecophysiology
before starting studying microorganisms at molecular level. During her master
internship, she worked on the replication helicase MCM from
Pyrococcus abyssi
, an
Euryarchaeota. As PhD student at Université de Sherbrooke (Québec), she is studying
DNA repair mechanisms and chromatin on
Saccharomyces cerevisiae.
Her main work
is analyzing the rRNA gene proteome linked to UV radiation and Nucleotide Excision
Repair to highlight proteins involved in chromatin repair-dependent modifications.
Alexia participated in two published papers and in in-redaction one.
e:
Alexia.Muguet@USherbrooke.caHydroxyurea arrests
Saccharomyces cerevisiae
cells in G1/early S-phase of the cell cycle and limits
rRNA synthesis
Alexia Muguet
1
, Romain Charton
1
, Joachim Griesenbeck
2
, Michael J. Smerdon
3
and
Antonio Conconi
1
1
Université de Sherbrooke, Canada
2
Universität Regensburg, Germany
3
Washington State University, United States