We use an integrated approach combining cell biology with biochemistry and biophysics to look at vesicle formation, secretory cargo selection, motor protein driven transport, and cell organization. All of our work uses various aspects of advanced imaging of fixed and living cells, including nanometre tracking, 3D rendering and deconvolution, as well as electron microscopy (with the Verkade lab). In particular, my lab is investigating the role of motor proteins in membrane positioning and vesicle trafficking, as well as asking fundamental questions about how and why the intracellular membranes of mammalian cells are organized as they are. Examples of our work include where we combined these approaches to demonstrate key roles for COPII in craniofacial development (4) and global cellular organization (3). A project is available to explore the role of the early secretory pathway in the secretion of extracellular matrix components (see 1) and the impact that this has on cell, tissue, and organism homeostasis (3). Our work focuses on the interface of membrane and cytoskeleton dynamics and the role that coordinated function of these two systems plays in secretory pathways.
Our work is housed in newly developed laboratory space with access to state of the art microscopy and proteomics facilities nearby. The project will exploit our advanced bioimaging technology available within the lab and the Wolfson Bioimaging Facility at the University of Bristol.
For further details see:
Stephens lab website: http://www.bristol.ac.uk/biochemistry/stephens/index.html
Funding Notes:
Additional studentships opportunities in the Stephens lab are also available for UK and EU students through the Wellcome Trust 4 Year PhD Programme in Dynamic Cell Biology. http://www.bris.ac.uk/fmvs/postgrad/wellcomefunding/
References:
1. Stephens, D.J. (2012) Cell Biology: Collagen secretion explained. Nature 482, 474-475. http://www.nature.com/nature/journal/v482/n7386/full/482474a.html doi:10.1038/482474a
2. Townley, A.K., Schmidt, K, Hodgson, L., and Stephens, D.J. (2012) Cell autonomous COPII-dependent secretion is required for epithelial differentiation and cyst lumen expansion. Journal of Cell Science. doi: 10.1242/jcs.091355 http://jcs.biologists.org/cgi/content/abstract/jcs.091355v1
3. Hughes, H., Budnik, A., Schmidt, K.J., Johnson, A., Noakes, C., Carter, D.A., Verkade, P., Watson, P., and Stephens, D.J. (2009) Organization of human endoplasmic reticulum exit sites: requirements for the localization of Sec16 to transitional ER. Journal of Cell Science 122, 2924-2934.
4. Townley, A.K., Feng, Y., Schmidt, K., Carter, D.A., R. Porter, Verkade, P., and Stephens, D.J. (2008) Efficient coupling of Sec23-Sec24 to Sec13-Sec31 drives COPII-dependent collagen secretion and is essential for normal craniofacial development. Journal of Cell Science 121, 3025-34.