Understanding structure-function relationships in the primary cilium using high content screening and super resolution microscopy

The School of Medicine (Prof. Colin Johnson - MP is co-supervisor) is seeking an enthusiastic PhD student to undertake research in molecular cell biology of a sub-cellular organelle called the primary cilium, with an emphasis on advanced imaging techniques. Cilia are finger-like projections from cells that act as a cellular “antenna” to detect and respond to chemical or mechanical cues. One important cue is fluid flow during the process of establishing asymmetry during early embryogenesis, the formation of the kidney nephron, and the formation of other tubular structures such as the neural tube. Primary cilia are regarded as cellular signalling hubs, regulating diverse signalling pathways, with particularly important roles during embryonic development. Cilia possess distinct molecular compositions and are enriched for many receptors, channels, and signaling components. In particular, the ciliary “transition zone” is a sub-compartment located at the most proximal 0.3-0.8 μm region of the cilium that is thought to control cilium composition and signalling by forming a protein diffusion barrier at the ciliary base.
The importance of the primary cilium has only become apparent in the last decade, and therefore processes involved in cilia formation and maintenance remain poorly understood. Defects in primary cilia are associated with heterogeneous inherited developmental conditions known as the ciliopathies that often present with diverse pathologies including cystic kidneys, blindness and nervous system defects. As a group, ciliopathies are comparatively common Mendelian inherited conditions with an overall estimated prevalence of 1 in 2000. By understanding the disease mechanisms for these conditions, we should gain new insights into more common diseases, including neural tube defects, retinal degeneration and obesity.
This project will use reverse genetics screening and super resolution microscopy to further characterize and understand the molecular composition and mechanisms contributing to ciliary organisation and barrier regulation. In the first instance, the student will complete a series of focused siRNA-based visual screens of cilium structure and function using high content imaging of appropriate cellular phenotypes. High content imaging will use a Perkin-Elmer “Operetta” system, based at the Leeds Institute of Biomedical and Clinical Sciences, and located at the St. James’s University Hospital campus. Potential screen hits will be confirmed by further rounds of secondary and validation screening, following by appropriate biochemical assays of function or protein-protein interaction. Detailed localization studies for ciliary proteins will then be possible with super resolution microscopy techniques, such as direct stochastic optical reconstruction microscopy (dSTORM). These studies will be based at the School of Molecular and Cellular Biology, Faculty of Biological Sciences. STORM is a single molecule sub-diffraction fluorescence imaging technique with a lateral resolution of ~20 nm and can therefore resolve components within the cilium. We envisage that this approach will provide unprecedented detail of structure-function relationships for protein trafficking and signalling processes at the primary cilium.
The student will receive training in high content imaging and biochemical techniques within the group. Prof. Peckham will be the microscopy expert supervisor, but the student will benefit from collaboration with other imaging and cell biology groups in Leeds. The Leeds group also have strong links with teams lead by Prof. Ronald Roepman at the Radboud University Medical Center, Nijmegen, and Dr. Oliver Blacque, University College Dublin.

Environment:
The student will be based at the University of Leeds in the Section of Ophthalmology & Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, located at the St. James’s University Hospital campus. Super resolution microscopy will be based at the School of Molecular and Cellular Biology, Faculty of Biological Sciences, located on the main university campus. The student will join large research groups with expertise in the relevant techniques, with the expectation that the successful candidate will attend advanced training courses and research conferences.