Dr Michelle Dunstone

NHMRC Peter Doherty Fellow

Joint appointment in Department of Biochemistry and Molecular Biology

Telephone: +61 3 9902 9269
Facsimile:   +61 3 9902 9500
Office:         Room 231, Level 2, Building 77
Email:         michelle.dunstone@med.monash.edu.au

Research Interests

Structural and bioinformatic studies of pore forming toxins and pathogen virulence factors.

Molecular Holepunchers: From Immunity To Bacterial Disease

In collaboration with Professor James Whisstock and Dr Ruby Law

Pore Forming Toxins (PFTs) are proteins commonly identified as bacterial virulence factors, proteins of the immune system and animal venoms (Rosado et al., Cellular Microbiology, 2008). These molecules possess the ability to change shape from water soluble single proteins to lipid membrane inserted ring-shapes consisting of 12 - 50 molecules. These ring-shapes act as pores in the target cell membrane that can result in death of the cell by lysis or delivery of other toxins. My lab focuses on the function of a recently united CDC/MACPF superfamily of pore forming toxins (Rosado et al., Science, 2007).

Model of how the MACPF protein domain is able to change shape. The red and yellow loops represent the region that can insert into the cell membrane thereby forming holes in the cell.

Projects: Projects on pore forming toxins aim to determine the pore structure of MACPF/CDC toxins. Comparison of the structures before and after pore formation will provide insight into the mechanism of function of all MACPF/CDC pore forming toxins in both disease and immunity. Lab skills taught include bioinformatics, molecular biology, protein chemistry, X-ray crystallography, cell lysis assays and cysteine fluorescence labelling studies.

http://en.wikipedia.org/wiki/Macpf

Structural Studies of the “Burger Bug”

In collaboration with Dr Elizabeth Hartland (Department of Immunology and Microbiology, University of Melbourne)

Enteropathogenic Escherichia coli (EPEC) is a pathogenic form of E. coli cause severe gastroenteritis particularly in children and immunocompromised people. Outbreaks of EPEC are synonymous with contaminated beef products such as undercooked beef burgers (the "burger bug"). EPEC attaches to the cells of the intestinal epithelium. EPEC uses the Type Three Secretion System (T3SS) to deliver many proteins, known as effectors, into the host cell. These effectors are used by EPEC to subvert cellular processes that are used by the pathogen to benefit pathogen replication and contribute to disease. However little is known about how these effectors function.

Projects: My lab aims to identify the mechanism of function of key effector proteins using X-ray crystallography in conjunction with cell biology techniques. Lab skills taught include bioinformatics, molecular biology, protein chemistry, X-ray crystallography, protein-protein interaction assays, cell biology and microscopy.

Information for Potential Students

If you have an interest in studying one of these projects please feel free to contact Michelle at anytime.

For more information about studying an Honours degree click here: http://www.med.monash.edu.au/biochem/teaching/hons-general.html

For more information about studying a Masters or PhD degrees click here: http://www.med.monash.edu.au/biochem/phd/

Selected Publications

• C.J. Rosado, S. Kondos, T.E. Bull, M.J. Kuiper, R.H.P. Law, A.M. Buckle, I. Voskoboinik, P.I. Bird, J.A.Trapani, J.C. Whisstock* and M.A. Dunstone* "The MACPF / CDC family of pore forming toxins." Cellular Microbiology (In press, 2008).

• C.J. Rosado, A.M. Buckle, R.H.P. Law, R.E. Butcher, W. Kan, C.H. Bird, K. Ung, K.A. Browne, K. Baran, T.A. Bashtannyk-Puhalovich, N.G. Faux, W. Wong, C.J. Porter, R.N. Pike, A.M. Ellisdon, M.C. Pearce, S.P. Bottomley, J. Emsley, A.I. Smith, J. Rossjohn, E.L. Hartland, I. Voskoboini, J.A. Trapani, P.I. Bird, M.A. Dunstone* and J.C. Whisstock$ "A common fold mediates vertebrate defense and bacterial attack." Science 317(5844):1548-51 (2007).

• F.M. Sansom, P. Riedmaier, H.J. Newton, M.A. Dunstone, C.E. Müller, H. Stephan, E. Byres, T. Beddoe, J. Rossjohn, P.J. Cowan, A.J. d'Apice, S.C. Robson, E.L. Hartland. "Enzymatic properties of an ecto-nucleoside triphosphate diphosphohydrolase from Legionella pneumophila: substrate specificity and requirement for virulence." Journal of Biological Chemistry 283(19) 12909-18 (2008).

• M.A. Dunstone*, C.S. Clements*, W.A. Macdonald, J. McCluskey and J. Rossjohn. "Specificity on a knife-edge: the alphabeta T cell receptor." Current Opinion in Structural Biology 16(6) 787-95 (2006).

• M.A. Dunstone*, L. Kjer-Nielsen*, L. Kostenko, L.K. Ely, T. Beddoe, N.A. Mifsud, A.W. Purcell, A.G. Brooks, J. McCluskey and J. Rossjohn. "Crystal structure of the human T cell receptor CD3 epsilon gamma heterodimer complexed to the therapeutic mAb OKT3."
  Proceedings of the National Academy of Sciences USA 101(20) 7675-80 (2004).

Click here for Michelle Dunstone's full publication record