DR. JENS R. COORSSEN

B.Sc. (Brock University), Ph.D. (McMaster University) - Associate Professor, Department of Physiology & Biophysics and Department Biochemistry & Molecular Biology.

Affiliations: Member - Cellular & Molecular Neurobiology Research Group.

Research Interests:

Delineation of the molecular mechanisms essential to exocytosis and endocytosis is critical to understanding a variety of disease states and to developing rational intervention strategies. My current work targets the Ca2+-triggered fusion steps. These studies utilize stage-specific model systems, permitting an integrated experimental approach combining techniques from physiology, proteomics, biochemistry, biophysics, molecular biology, and physical chemistry, together with specific, sensitive functional assays. Through collaborative work with colleagues at the NIH, these studies have shown that while certain proteins promote efficient exocytosis, they are not essential to the triggered fusion steps. By identifying essential conserved components, I hope to advance our understanding of synaptic function (including plasticity) and the regulation of secretion in other cell types. To this end, my collaborators and I at the University of Calgary, have also undertaken a functional proteomic analysis of the molecular mechanisms underlying simple forms of learning and memory.

View Pub Med for Recent publications & abstracts

Recent Publications:

• Coorssen, J.R., Blank, P.S., Albertorio, F., Bezrukov, L., Kolosova, I., Backlund, P. and Zimmerberg, J. (2002) Quantitative femto- to attomole immunodetection of regulated secretory vesicle proteins critical to exocytosis. Anal. Biochem., 307: 54-62.
• Yergey, A.L., Coorssen, J.R., Backlund, P.S., Blank, P.S., Humphrey, G.A., Zimmerberg, J., Campbell, J.M., and Vestal, M. (2002) De novo sequencing of peptides using MALDI-TOF/TOF.  (J. Am. Soc. Mass Spectrom 13: 784-791.
• Coorssen, J.R., Blank, P.S., Albertorio, F., Bezrukov, L., Kolosova, I., Chen, X., Backlund, P. and Zimmerberg, J. (2002) Establishing the inherent calcium activity of a native secretory vesicle fusion machine: SNAREs modulate calcium sensitivity. (J. Cell Sci., submitted).
• Szule, J.A. and Coorssen, J.R. (2002) Roles of SNAREs proteins in exocytosis and fusion. (Requested review for a special membrane fusion issue of BBA; submitted).
• Timmers, K., Whalley, T., Coorssen, J.R., Kingsley, D.H., and Zimmerberg, J.(2002) Membrane fusion of secretory vesicles of the sea urchin egg in the absence of NSF. (J. Biol. Chem., submitted).
• Zimmerberg, J., Blank, P.S., Kolosova, I., Cho, M.S., Tahara, M. and Coorssen, J.R. (2000). Stage-specific preparations to study the Ca2+-triggered fusion steps of exocytosis: rationale and perspectives. Biochimie 82: 303-314.
• Zimmerberg, J., Coorssen, J.R., Vogel, S.S. and Blank, P.S. (1999). Sea urchin egg preparations as systems for the study of calcium-triggered exocytosis.  J. Physiol., 520.1: 15-21.
• Coorssen, J.R., Blank, P.S., Tahara, M. and Zimmerberg, J. (1998). Biochemical and functional studies of cortical vesicle fusion: The SNARE complex and Ca2+ sensitivity.  J. Cell Biol. 143, 1845-1857.
• Scepek, S., Coorssen, J.R. and Lindau, M. (1998). Fusion pore expansion in horse eosinophils is modulated by Ca2+ and protein kinase C via distinct mechanisms. EMBO J. 17: 4340-4345.
• Tahara, M., Coorssen, J.R., Timmers, K., Blank, P.S., Whalley, T., Scheller, R. and Zimmerberg, J. (1998). Calcium disrupts the SNARE protein complex on sea urchin egg secretory vesicles without irreversibly blocking fusion.  J. Biol. Chem. 273, 33667-33673.
• Coorssen, J.R., Schmitt, H. and Almers, W. (1996). Ca2+ triggers massive exocytosis in Chinese hamster ovary cells.  EMBO J. 15: 3787-3791.
• Coorssen, J.R. (1996). Phospholipase activation and secretion: Evidence that PLA2 , PLC, and PLD are not essential to exocytosis.  Am. J. Physiol. 270: C1153-C1163.

Contact Information:

The University of Calgary,
Room 174 Heritage Medical Research Building,
3330 Hospital Drive NW, Calgary,
Alberta Canada T2N 4N1
Phone: (403) 220-2422
Fax: (403) 283-7137
E-mail: jcoorsse [at] ucalgary [dot] ca.