Milena Timcenko Tronsgaard: Razor-sharp electron images lead to first structure of lipid-flipping protein

Figure 1: An image of the studied protein from cryo-electron microscopy – the protein is the white, threaded figure in the center. The image is an made by combining thousands of single images taken from the same angle. The magnification shown here corresponds approximately to seeing a Danish five-kroner coin covering the island of Funen.

29 July 2019 by Lisbeth Heilesen

During her studies, Milena Timcenko has investigated the structure of a family of proteins called lipid flippases. Cell membranes are made up of a double-layer of lipids, where the hydrophilic lipid headgroups shield the fatty acid tails of the lipids from exposure to water. The role of the lipid flippases is to regulate the distribution of specific lipids between the two sides of a membrane, and if they are disrupted it can lead to numerous diseases like diabetes, neurodegeneration or cancer.

Milena has used cryo-electron microscopy to study the atomic structure of a lipid flippase from yeast. This relatively new technique allows individual protein molecules (which are ~20 nm long) to be imaged using electrons. The results of this basic research – the determination of the first structure of a lipid flippase – contributes to further the understanding of how these proteins function, and it can serve as a foundation for future investigation of this essential protein family.

The PhD degree was completed at the Department of Molecular Biology and Genetics, Science and Technology, Aarhus University.

This résumé was prepared by the PhD student.

Time: Monday 29 July 2019 at 13.00
Place: Building 1593-012, iNANO Auditorium, Gustav Wieds Vej 14, 8000 Aarhus C
Title of PhD thesis: Structural studies of the yeast lipid flippase, Drs2p/Cdc50p, using cryo-electron microscopy
Contact information: Milena Timcenko (previously Laban), e-mail: milena@mbg.au.dk, tel.: +45 3013 4619
Members of the assessment committee:
Professor Thomas Günther-Pomorski, Institut for Plante- og Miljøvidenskab, Københavns Universitet
Professor John L. Rubinstein, Department of Biochemistry, University of Toronto, Canada
Associate Professor Ernst-Martin Füchtbauer, Institut for Molekylærbiologi og Genetik, Aarhus Universitet
Main supervisor:
Professor Poul Nissen, Department of Molecular Biology and Genetics, Aarhus University
Co-supervisor:
Assistant Professor Joseph Lyons, Department of Molecular Biology and Genetics, Aarhus University
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Science and Technology/GSST, Ny Munkegade 120, building 1521, 8000 Aarhus C.