François Dragon

François Dragon

Département des sciences biologiques

Poste : Professeur

Courriel : dragon.francois@uqam.ca

Téléphone : (514) 987-3000 poste 2063

Local : SB-3325

Domaines d'expertise

  • Biologie moléculaire et cellulaire
  • Génétique moléculaire
  • Nucléole
  • Ribosome
  • Ribonucléoprotéines

Langues

  • Français
  • Anglais
Informations générales

Cheminement académique

1999-2001: Post-doctorat en Génétique moléculaire, Laboratoire de Dr Susan J. Baserga, Departments of Therapeutic Radiology and Genetics, Yale University School of Medicine (New Haven, CT, U.S.A.)

1995-1999: Post-doctorat en Biologie moléculaire et cellulaire, Laboratoire de Dr Witold Filipowicz, Friedrich Miescher Institute for Biomedical Research (Bâle, Suisse)

1988-1995: Maîtrise et Doctorat en biochimie, Laboratoire de Dr Léa Brakier-Gingras, Département de biochimie, Université de Montréal

1984-1987: Baccalauréat en biochimie, Université du Québec à Montréal

Unités de recherche

  • Centre de recherches biomédicales (BIOMED)

Projets de recherche en cours

  • Le rôle de facteurs nucléolaires dans la biogenèse des ribosomes

    Ribosomes are the organelles that synthesize proteins in all living organisms. They are formed by the association of two subunits (a small and a large) that are constituted of large RNA molecules and multiple proteins. The key components of ribosomes are the ribosomal RNAs (rRNAs) as they are directly involved in the different steps of protein synthesis. The biogenesis of ribosomes is a major cellular process, and it is a prerequisite for cells to grow in size and proliferate. In eukaryotes, this process takes place in the nucleolus, a prominent compartment of the cell nucleus. The majority of nucleolar factors actually function at various steps of the intricate pathway that leads to the production of mature rRNAs. My research program focuses on ribosome biogenesis in the yeast Saccharomyces cerevisiae, the best studied eukaryotic model system in the field. Work in my laboratory contributes to defining the molecular mechanisms involving nucleolar factors that participate in the production of mature rRNAs. In particular, we focus on the cleavage reactions that remove extra sequences from precursor rRNA molecules. My lab is using yeast as a model system to take advantage of its well-characterized genetic, biochemical and molecular biology tools. Our objective for the next five years is to define the role of three nucleolar enzymes: Dbp4, Kre33 and Nop38. Dbp4 is an RNA helicase that acts as a molecular motor to rearrange RNA-RNA (or possibly RNA-protein) interactions during the pre-rRNA cleavage steps. Importantly, Dbp4 is associated with other nucleolar factors that are conserved among species: all are essential for growth, indicating that they perform crucial cellular functions. Human homologues of these proteins are involved in embryonic development and cancer (the human homologue of Dbp4, DDX10, has been identified as a "cancer gene"). Kre33 is a putative RNA acetyltransferase that is conserved from bacteria to humans. This high degree of conservation suggests it has a critical cellular function but almost nothing is known about the role of Kre33 in yeast. My lab identified specific features of Kre33 that distinguish it from its bacterial ancestors, and we suspect these are key elements for the function of Kre33 in yeast and humans. To determine how Kre33 functions at the molecular level we will combine genetic and biochemical approaches. These investigations are fundamental to understand why Kre33 is essential for cell survival. Nop38 is a putative RNA methyltransferase that is highly conserved but not as much as Kre33. Nop38 is present in yeasts, plants, animals but it is not found in all bacteria, only those termed ¿extremophiles¿, which live in very hostile environments such as oceanic thermal vents; ¿normal¿ bacteria, like those that live in the guts of animals, do not have Nop38. We are very excited to work on this enzyme because nothing is known about its function, and everything remains to be discovered. Our research on Dbp4, Kre33 and Nop38 is important to understand how these proteins function in the cell: elucidation of molecular mechanisms underlying ribosome biogenesis in eukaryotes could open new avenues to improve the growth of plants, to treat diseases or to target eukaryotic pathogens that affect humans and other animals.

Enseignement et supervision
Publications

Soltanieh, S., Osheim, Y.N., Spasov, K., Trahan, C., Beyer, A.L. et Dragon, F. (2015). DEAD-box RNA helicase Dbp4 is required for small-subunit processome formation and function. Molecular and Cellular Biology, 35(5), 816–830. http://dx.doi.org/10.1128/MCB.01348-14.


Ban, N., Beckmann, R., Cate, J.H., et al. (2014). A new system for naming ribosomal proteins. Current Opininion in Structural Biology, 24, 165–169. http://dx.doi.org/10.1016/j.sbi.2014.01.002.


Soltanieh, S., Lapensée, M. et Dragon, F. (2014). Nucleolar proteins Bfr2 and Enp2 interact with DEAD-box RNA helicase Dbp4 in two different complexes. Nucleic Acids Research, 42(5), 3194–3206. http://dx.doi.org/10.1093/nar/gkt1293.


Lemay, V., Hossain, A., Osheim, Y.N., Beyer, A.L. et Dragon, F. (2011). Identification of novel proteins associated with yeast snR30 small nucleolar RNA. Nucleic Acids Research, 39(22), 9659–9670. http://dx.doi.org/10.1093/nar/gkr659.


Trahan, C., Martel, C. et Dragon, C. (2010). Effects of dyskeratosis congenita mutations in dyskerin, NHP2 and NOP10 on assembly of H/ACA pre-RNPs. Human Molecular Genetics, 19(5), 825–836. http://dx.doi.org/10.1093/hmg/ddp551.


Trahan, C. et Dragon, F. (2009). Dyskeratosis congenita mutations in the H/ACA domain of human telomerase RNA affect its assembly into a pre-RNP. RNA, 15, 235–243. http://dx.doi.org/10.1261/rna.1354009.


Osheim, Y.N., French, S.L., Keck, K.M., et al. (2004). Pre-18S ribosomal RNA is structurally compacted into the SSU processome prior to being cleaved from nascent transcripts in Saccharomyces cerevisiae. Molecular Cell, 16(6), 943–954. http://dx.doi.org/10.1016/j.molcel.2004.11.031.


Dragon, F.G., J.E., Compagnone-Post, P.A., Mitchell, B.M., et al. (2002). A large nucleolar U3 ribonucleoprotein required for 18S ribosomal RNA biogenesis. Nature, 417, 967–970. http://dx.doi.org/10.1038/nature00769.


Dragon, F., Lemay, V. et Trahan, C. (2006). Biogenesis, Structure and Function. Encyclopedia of Life Sciences. Chichester, UK : John Wiley and Sons.


Filipowicz, W., Pelczar, P., Pogacic, V. et Dragon, F. (1999). Biogenesis, structure and function of small nucleolar RNAs. Dans J. Barciszewski et B.F.C. Clark (dir.). RNA Biochemistry and Biotechnology (p. 291–302). Dordrecht : Kluwer Academic Publishers.


Distinctions
  • Chercheur-boursier Junior II (2005-2008)
  • Chercheur-boursier Junior I (2003-2005)
  • Bourse post-doctorale, Anna Fuller Fund for Molecular Oncology, Yale Cancer Center (1999-2001)

Intérêts de recherche

Département des sciences biologiques

Le Département des sciences biologiques de l’UQAM est l’un des départements les plus dynamiques au Canada, profitant d’un des plus haut taux de subventions de recherche. La plupart de ses chercheurs sont regroupés au sein d’équipes de recherche de pointe en écologie, santé environnementale et toxicologie, et biotechnologies.

Coordonnées

Département des sciences biologiques
Local SB-R860
141, Avenue du Président-Kennedy
Montréal (Québec) H2X 1Y4