Rene E. Harrison
Ph.D. (University of Toronto)

Associate Professor in Zoology
Phone: 416-287-7377
Fax: 416-287-7676
e-mail: harrison@utsc.utoronto.ca 		 



Research Focus

My research interests are in the area of cell polarity. Reorganization of cytoplasm and creation of unique plasma membrane domains is a shared phenomenon amongst various cell types to carry out their specialized functions. Such dramatic cell shape changes are orchestrated by the cytoskeleton, principally microtubules which extend throughout the cytosol. This proteinaceous network serves as a conduit for the delivery of key signaling proteins and membrane elements required for the consequent cell surface morphological changes.



Current Research Projects

I am currently studying the cytoskeleton in cell polarization in several cell types: macrophages, osteoclasts and neurons. Macrophages are crucial front-line cells in the body’s defense against infection. Macrophages destroy pathogens by phagocytosis, a process whereby pathogens are engulfed by extensive plasma membrane extensions, called pseudopods. Pseudopods develop at the site of plasma membrane attachment to the pathogen and polarized fusion of intracellular membrane stores at this site allow the pseudopods to surround and internalize the target pathogen.
Osteoclasts are bone cells function to focally target acidic organelles to the bone apposed plasma membrane region. Fusion of these acidic organelles with the basal plasma membrane creates a highly asymmetric cell surface, termed the ruffled border, which serves as the bone-resorbing organelle. While osteoclasts are crucial for calcium store release and normal bone remodeling, these cells are also the highly destructive instigators of bone degeneration in diseases including osteoporosis, rheumatoid arthritis, multiple myeloma and metastatic cancers.
Neurons are one of the most polarized cell types in the body: with cell processes extending up to metres away from the cell body. Neuronal function depends on trafficking of secretory vesicles containing neurotransmitters to the ends of the extensive cell processes. Understanding the molecular regulation of secretory vesicle trafficking is key to understanding neuronal disorders where neurotransmitter release is impaired.
Microtubules are implicated in the trafficking of organelles to the active plasma membrane region of all of these cells. We are studying microtubule-associated proteins, microtubule motors and signaling elements responsible for this translocation.



Research Opportunities

I am taking CV’s from interested graduate students and postdoctoral fellows.


Research Group

Arian Khandani, M.Sc.
Edward Eng
David Douda
Salma Rawof
Payman Tehrani

Research Assistant
Ph.D. Student
M.Sc. student
4th Year Project Student
4th Year Project Student
   


Recent Publications

  • Nabavi N., Urukova Y., Cardelli M., Aubin J.E. & Harrison R.E. (2008) Lysosome dispersion in osteoblasts accommodates enhanced collagen production during differentiation. J Biol Chem, 283, 19678.
  • Patel P.C. & Harrison R.E. (2008) Membrane ruffles capture C3bi-opsonized particles in activated macrophages. Mol Biol Cell, 19, 4628.
  • Binker M.G., Zhao D.Y., Pang S.J. & Harrison R.E. (2007) Cytoplasmic linker protein-170 enhances spreading and phagocytosis in activated macrophages by stabilizing microtubules. J Immunol, 179, 3780.
  • Eng E.W., Bettio A., Ibrahim J. & Harrison R.E. (2007) MTOC reorientation occurs during FcgammaR-mediated phagocytosis in macrophages. Mol Biol Cell, 18, 2389.
  • Khandani A., Eng E., Jongstra-Bilen J., Schreiber A.D., Douda D., Samavarchi-Tehrani P. & Harrison R.E. (2007) Microtubules regulate PI-3K activity and recruitment to the phagocytic cup during Fcgamma receptor-mediated phagocytosis in nonelicited macrophages. J Leukoc Biol, 82, 417.
  • Touret N., Paroutis P., Terebiznik M., Harrison R.E., Trombetta S., Pypaert M., Chow A., Jiang A., Shaw J., Yip C., Moore H.P., van der Wel N., Houben D., Peters P.J., de Chastellier C., Mellman I. & Grinstein S. (2005) Quantitative and dynamic assessment of the contribution of the ER to phagosome formation. Cell, 123, 157.
  • Harrison R.E., Brumell J.H., Khandani A., Bucci C., Scott C.C., Jiang X., Finlay B.B. & Grinstein S. (2004) Salmonella impairs RILP recruitment to Rab7 during maturation of invasion vacuoles. Mol Biol Cell, 15, 3146.
  • Vieira O.V., Harrison R.E., Scott C.C., Stenmark H., Alexander D., Liu J., Gruenberg J., Schreiber A.D. & Grinstein S. (2004) Acquisition of Hrs, an essential component of phagosomal maturation, is impaired by mycobacteria. Mol Cell Biol, 24, 4593.
  • Harrison R.E., Bucci C., Vieira O.V., Schroer T.A. & Grinstein S. (2003) Phagosomes fuse with late endosomes and/or lysosomes by extension of membrane protrusions along microtubules: role of Rab7 and RILP. Mol Cell Biol, 23, 6494.
  • Jongstra-Bilen J., Harrison R. & Grinstein S. (2003) Fcgamma-receptors induce Mac-1 (CD11b/CD18) mobilization and accumulation in the phagocytic cup for optimal phagocytosis. J Biol Chem, 278, 45720.
  • Harrison R.E., Touret N. & Grinstein S. (2002) Microbial killing: oxidants, proteases and ions. Curr Biol, 12, R357.
  • Harrison R.E. & Grinstein S. (2002) Phagocytosis and the microtubule cytoskeleton. Biochem Cell Biol, 80, 509.


Teaching

  • BGYB10 Cell Biology