Quantitative in vivo analysis of ligand-receptor interactions in the Wnt signalling network

Lead Research Organisation: University of Exeter
Department Name: Biosciences

Abstract

Cell-cell communication is essential for the regulation of the development and homeostasis of all multicellular organisms. Secreted signals like Wnt signals regulate fundamental processes including cell proliferation and differentiation, cell polarity and migration. Misregulation of this signalling network causes severe diseases like neurodegenerative diseases like Alzheimer's disease. Binding of a Wnt ligand with a seven-pass transmembrane Frizzled (Fzd) receptor on the surface of cells is the principal way to activate the Wnt signalling network. 19 different Wnt ligands may bind to 10 different Fzd receptors to specify the nature of the downstream signalling event. Accurate quantification of these interactions in living cells is crucial to understand signalling specificity, however, due to technical obstacles, this was not possible until today.
In collaboration with Leica Microsystems and under the supervision of cell biologists and biophysicists, we will employ correlation spectroscopy to quantify for the first time the effective binding affinities - Kd (effective) - between three Wnt ligands and three different Fzd proteins in vivo. The student will apply molecular biological techniques such as mRNA overexpression and CRISPR/Cas9- based knock-out methods in neurons to visualize ligands and receptors. Then we will use imaging-based, quantitative measurements of ligand-receptor interaction in cells e.g. neurons and in zebrafish by fluorescence fluctuation techniques. In a collaboration with the R&D unit of Leica, the student will develop and refine Leica's single-molecule detection unit FALCON for its usage in the living specimen.
The student selected for this project will develop invaluable skill sets in experimental genetics, in vivo techniques, biophysical methods such as spectroscopy and microscopy, whilst also making a significant contribution to the understanding of the Wnt signalling network. This combined skill set including the interactions with the industrial partner will make the candidate a highly desirable recruitment prospect for future academic and industrial
employers.
The Living Systems Institute (LSI), with complementary expertise in biosciences and physics, will be an optimal environment to conduct these doctoral training studies. The LSI offers unique training opportunities for the PhD student as it allows the student to address key problems in life sciences with state-of-the-art equipment in an interdisciplinary environment. The project includes close collaboration with the universities of Cardiff, London (KCL) and Bristol to compliment the required skill sets.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M009122/1 01/10/2015 31/03/2024
2240970 Studentship BB/M009122/1 01/10/2019 31/10/2023 Michael Dawes
 
Description A novel method for identifying proteins on cell surface projections has been developed and optimised. This method provides a non-biased approach to a previously difficult to achieve problem. The method will provide further insight to how cells communicate to other cells across short distances using signalling proteins, specifically Wnt signalling proteins.
Exploitation Route the design of this method is transferable to all signalling molecules that require handover between cells. the design is simple to implement and non-biased, therefore novel proteins found by this method can be used to direct novel therapeutic targets or generate new avenues for research.
Sectors Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology,Other

URL https://link.springer.com/article/10.1007/s00418-020-01930-5
 
Description We have developed a novel tool for identifying proteins that are specific to cell-cell communication through single signalling proteins. The strength of this tool is the specificity of tagging proteins that are involved in mature signalling of the protein of interest and its ability to be used for any protein of interest to the researcher.
First Year Of Impact 2019
Sector Healthcare,Pharmaceuticals and Medical Biotechnology