Associate Director, Lady Davis Institute
James McGill Professor of Medicine and Oncology, McGill University
Dr. Stéphane Richard, Ph.D., FRSQ Chercheur National, is a James McGill Professor of Medicine and Oncology at McGill University and an Associate Director of Research at the Lady Davis Institute for Medical Research at the Jewish General Hospital in Montreal.
Major Research Activities
Dr. Richard is interested in elucidating the role of protein arginine methylation in epigenetics and DNA damage signaling (see Mol Cell 18:263, 2005). Dr. Richard and his coworkers developed key reagents that permitted them to study the extent of protein arginine methylation (Mol Cell Proteomic 2:1319, 2003). In a proteomic study, they identified more than 200 methylated proteins at which time there were about 20 known proteins. These findings demonstrated that arginine methylation is a common post-translational modification and this led to the increase in visibility of protein methylation.
Dr. Richard and coworkers reported that proteins involved in repairing damaged DNA were methylated (Genes&Dev 19:671, 2005). They also showed that methylation of these key DNA damage proteins is essential for their function and to maintain genomic stability (Mol & Cell Biol 29:2982, 2009). These findings have implications for cancer treatment, as inhibitors of protein arginine methyltransferase may synergize with chemotoxic agents to increase the efficacy of treatment. They also discovered that arginine methylation can regulate protein sub-cellular localization (Mol Biol Cell 14:274, 2003), protein to protein interactions (J Biol Chem 275:16030, 2000), and pre-mRNA splicing (J Cell Biol 159:957, 2002). They also identified a subset of signaling proteins that associate with arginine methylated proteins (J Biol Chem 280:28476, 2005). They are actively defining the role of arginine methylation in gene regulation and the maintenance of genomic stability.
Dr. Richard and coworkers defined a new signaling cascade that transmits signals from the extracellular milieu to the RNA binding protein, Sam68. This pathway allows the cell to rapidly alter its RNA metabolism in response to external cues (Mol & Cell Biol 15: 186, 1995). Dr. Richard's group elucidated the molecular mechanisms by which Sam68 signals to the cell interior. They demonstrated that Sam68 relocalizes from the nucleus to the plasma membrane to associate with Src kinases in response to specific extracellular cues, becoming an adaptor protein for local tyrosine kinases such as Src family kinases (Mol & Cell Biol 29:1933, 2009). This work defined a new property of RNA-binding proteins as adaptor proteins and explained how Sam68 can rapidly link the environment to intracellular signal transduction. Dr. Richard's laboratory also showed that Sam68 localizes to a novel nuclear structure, termed the Sam68 nuclear body, present only in cancer cells, and is likely to regulate nuclear RNA metabolism (Mol Biol Cell 10:3015, 1999).
In studies of mice lacking the Sam68 gene, Dr. Richard and colleagues demonstrated that Sam68-signalling is essential for normal brain development (Behav Brain Res 189:357, 2008; PLoS Genet e74, 2005), the maintenance of bone mass (PLoS Genet e74, 2005), and spermatogenesis (J Cell Biol 185:235, 2009), as well as contributing to protection against breast cancer (Oncogene 27:548, 2008). These findings have important implications for the role of this RNA binding protein in genetically complex human diseases. Dr. Richard and coworkers are actively defining the molecular and cellular roles of Sam68 in metabolic diseases and cancer.
Dr. Richard and colleagues reported that QKI is essential for the normal myelination of the central nervous system, since mutations in the QKI gene in mice impair its expression in oligodendrocytes and leads to the quaking viable mouse phenotype. They showed that these mice harbor a defect in QKI expression in oligodendrocytes at the time of central nervous system myelination (Neuron 36:815, 2002; Nature Neurosci 8:27, 2005). This research on QKI has provided a new perspective on RNA binding proteins in oligodendrocyte physiology (Trends Genet 24:416, 2008).
Dr. Richard and coworkers reported the identification of genes bound by QKI in the entire genome (Nat Struct Mol Biol 12:691, 2005). There are more than 1000 RNA targets that were found further linking QKI to the process of myelination, thus defining a new role for QKI in cancer. Dr. Richard and coworkers are actively defining the molecular targets regulated by the QKI RNA binding proteins in normal and diseased cells.
Recent Publications
Darbelli L and S. Richard. 2016. Emerging functions of the Quaking RNA binding proteins and link to human diseases. WIREs RNA 2016 Mar 14. doi: 10.1002/wrna.1344
Neault M, F.A. Mallette and S. Richard. 2016. miR-137 modulates a tumour suppressor network inducing senescence in pancreatic cancer cells. Cell Reports 14:1966-78
Blanc RS, G. Vogel, C. Crist and S. Richard. 2016. PRMT7 preserves satellite cell regeneration capacity. Cell Reports 14:1528-39
Darbelli, L, G. Vogel, G. Almazan and S. Richard. 2016. Quaking regulates neurofascin 155 expression for myelin and axoglial junction maintenance. J Neurosci 36:4106-20
Thandapani, P./J. Song, V. Gandin, Y. Cai, S. G. Rouleau, , J.-M. Garant, F.-M. Boisvert, Z. Yu, J.-P. Perreault, I. Topisirovic, and S. Richard. 2015. Aven recognition of RNA G-quadruplexes regulates translation of the mixed lineage leukemiaprotooncogenes. eLife 2015;10.7554/eLife.06234
Calibretta, S and S. Richard. 2015. Emerging roles of disordered sequences in RNA-binding proteins. Trends BiochemSci 40:662-72