Translational Research - Université de Genève

Bacteriology
Patrick Viollier
Department of Microbiology and Molecular Medicine
Patrick Viollier graduated in 1999 with a PhD in Microbiology from the Biozentrum, University
of Basel. After a four-year postdoctoral course at the Stanford University School of Medicine
he joined the Case Western Reserve University School of Medicine as Assistant Professor in
2004. In 2009 he was appointed Associate Professor in the Department of Microbiology and
Molecular Medicine at the Faculty of Medicine.
Bacterial cell cycle control
We study the molecular mechanisms that coordinate events during the bacterial cell division
and developmental cycle using a powerful genetic and synchronisable model system: the
dimorphic alpha-proteobacterium Caulobacter crescentus. In the past we relied on
comprehensive forward genetic and cell biological approaches to uncover polarity factors that
couple polar differentiation with the cell division cycle in Caulobacter. We also identified an
oxido-reductase-like cytokinetic regulator that coordinates cell division with the differentiation
programme in response to NAD(H) and found that diffusion barrirers can exist within bacterial
subcellular compartment (stalk, green) cells that have a volume in the femtoliter range.
We now also use Caulobacter to explore how bacteriophages (black arrow) seize the cell cycle
machinery, to illuminate how viral-host replication cycles are coordinated at the most
fundamental level.
14 Université de Genève • Faculté de médecine
Hughes HV, Huitema E, Pritchard S, Keiler K, Brun YV and Viollier PH (2010) Protein localization
and dynamics within a bacterial organelle. PNAS 107:5599-604.
Radhakrishnan SK, Pritchard S and Viollier PH (2010) Coupling prokaryotic cell fate cell fate and
division control by a bifunctional and oscillating oxido-reductase homolog.
Dev Cell 18:90-101.
Radhakrishnan SK, Thanbichler M and Viollier PH (2008) The dynamic interplay between a cell
fate determinant and a lysozyme homolog drives the asymmetric division cycle of
Caulobacter crescentus. Genes Dev. 22: 212-25.
Huitema E, Matteson D, Pritchard S, Kumar Radhakrishnan S and Viollier PH (2006) Bacterial
birth scar proteins mark future flagellum assembly site. Cell 124:1025-37.
Holtzendorff J, Hung D, Brende P, Reisenauer A, Viollier PH, McAdams HH and L. Shapiro (2004)
Oscillating Global Regulators Control the Genetic Circuit Driving a Bacterial Cell Cycle.
Science 304(5673):983-7.
Contact: Patrick.Viollier@unige.ch
Bacteriology
Université de Genève • Faculté de médecine
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