PhD Defence Christos Theodorou
You are invited for the PhD defence of Christos Thedorou
The title of his PhD thesis is: Untargeted Metabolomics as a tool for the elucidation of transporter protein substrate specificity
Summary:
In plants, transporter proteins are involved in multiple cellular processes such as maintaining homeostasis, signalling and cell communication as well as uptake or efflux of specialized metabolites among different compartments. However, our knowledge about the function of the many transporters in the genomes is limited. In the DynaMo Center, Christos Theodorou has been part of the VILLUM investigator project aimed at identification of transporter substrate specificity in a major transportomics endeavor.
Christos has played a key role in development of a novel transportomics methodology that combines the use of uptake assays with plant extracts as complex substrate mixtures, and untargeted metabolomics as an analytical tool, therefore allowing for the simultaneous testing of multiple compounds against the same transporter. In the thesis, Christos describes all steps, from the creation of the substrate mixture to the generation of the analytical pipeline for screening transporter proteins with the ‘transportomics’ pipeline. This includes the experimental set-up and the subsequent data acquisition, preprocessing and statistical analysis techniques comprising the developed pipeline based on a dataset of transporter proteins with unknown functionality.
Christos has conducted a thorough investigation on different extracts that can be used as substrate mixtures in the transportomics pipeline and use an innovative approach to maximize the metabolic diversity contained within that mixture. He performed an in-depth metabolic profiling of the selected plant extract based on a combinatorial technique leading to the identification of more than 200 metabolites.
Through collaboration with other members who are part of this VILLUM investigator grant, the performance of the developed pipeline was validated based on two different study cases that are used as a proof of concept and present the first-of-its-kind export transportomics assay. Several substrates for four different transporter proteins belonging to different protein families were identified.
Principal supervisors:
Professor Barbara Ann Halkier, Section for Molecular Plant Biology
Facility manager Christoph Crocoll, Section for Molecular Plant Biology
Assessment committee:
Associate professor Giorgia La Barbera, Department of Nutrition and Health (Chair)
Professor Robert David Hall, Wageningen University and Research, the Netherlands (External member)
Assistant professor Daniel Petras, Department of Biochemistry, University of California, US (External member)