Translational Research - Université de Genève

Mycology
Martine A. Collart
Department of Microbiology and Molecular Medicine
Martine Collart obtained her PhD in 1990 at the University of Geneva. She continued her
research at Harvard Medical School in Boston with Kevin Struhl, where she identified the NOT
genes using a genetic selection in yeast. In 1993 she started her own independent group to
pursue the characterisation of the Not genes, in the Department of Medical Biochemistry of
the Faculty of Medicine at the University of Geneva. She was appointed Associate Professor in
the Department of Microbiology and Molecular Medicine in 2004 and full Professor in 2011.
Genetic and Biochemical characterisation of the conserved Ccr4-Not complex in yeast
We work on characterising, in the yeast S. cerevisiae, the function of an essential multisubunit
protein complex that is conserved across the eukaryotic kingdom, the Ccr4-Not complex. This
complex has two known enzymatic activities, ubiquitination provided by the RING finger Not4
E3 ligase, and deadenylation provided by the Caf1 and Ccr4 subunits. Despite growing
knowledge on these enzymatic functions, the role of the other subunits, the relationship
between the different subunits and their activities, and the reason for the association of these
different subunits in a complex is unknown. Our more recent experiments suggest that this
complex may serve as a chaperone allowing the assembly of multicomponent complexes in
cells. The tremendous complexity of this system in which a multisubunit complex regulates
assembly of other multisubunit complexes in eukaryotic cells, makes the yeast S. cerevisiae a
perfect model organism for study because of its powerful genetics that can be combined with
biochemistry.
50 Université de Genève • Faculté de médecine
Panasenko OO and Collart MA (2012) Presence of Not5 and ubiquitinated Rps7A in polysome
fractions depends upon the Not4 E3 ligase. Mol. Microbiol. 83: 640-632.
Collart MA and Panasenko OO (2012) The Ccr4-Not complex. Gene 492: 42-53.
Olesya O. Panasenko and Martine A. Collart (2011) Not4 E3 ligase contributes to proteasome
assembly and functional integrity via the Ecm29 chaperone. Mol. Cell. Biol. 31: 1610-1623.
Azzouz N, Panasenko OO, Colau G and Collart MA (2009) The Ccr4-Not complex physically and
functionally interacts with TRAMP and the nuclear exosome. PLoS One 4:e6760.
Panasenko OO, David F and Collart MA (2009) Ribosome association and stability of the nascent
polypeptide-associated complex is dependent upon its own ubiquitination. Genetics 181:
447-460.
Contact: Martine.Collart@unige.ch
Mycology
Université de Genève • Faculté de médecine
51