Public Guest talk: Prof. Dr. Roland Winter, TU Dortmund University

The RTG welcomes Prof. Dr. Roland Winter from the TU Dortmund University as a Guest Speaker on Tuesday, 13th of June 2017.

Title: “Membrane-Associated Signaling Processes and Fibrillation Reactions of Amyloidogenic Peptides”

Ras proteins, such as N- and K-Ras, are membrane-bound small GTPases which regulate a variety of cellular processes including cell growth, survival and differentiation. Mutations in RAS genes, which render Ras proteins constitutively active, are found in 30% of human cancers. In a combined chemical-biological and biophysical approach we explored the free energy contributions to the membrane partitioning of Ras proteins, and compared the theoretical predictions with experimental data on the membrane insertion of Ras proteins of various anchor systems into rationally designed model and natural membrane systems.

Various factors fostering or reducing the membrane partitioning properties are discussed, including hydrophobic effects, lipid chain mismatch, electrostatic interactions, membrane-mediated protein-protein interactions, and terms that account for line tension effects between coexisting lipid domains and lipid sorting, and change the lateral organization of the lipid bilayer system. In the second part of the presentation, effects of solution and confinement conditions on the various stages of the aggregation and fibrillation reaction of amyloidogenic peptides are discussed. Then, mechanistic details of the nucleation process and concurrent aggregation pathways of disease related amyloidogenic peptides, such as IAPP, and the differential stability of the aggregate structures formed are discussed in the absence and presence of model biomembrane systems of different complexity. We show that next to macromolecular crowding, also solvational perturbations, accomplished by the addition of various osmolytes, exert pronounced and diversified effects on the non-native assembly and fibril formation, which ultimately manifest in morphological variations of the mature aggregates and fibrils.

Official Announcement: RTG1962_Winter

Venue: Department Biology, Building B1, Floor 00, Seminar Room Cell Biology (00.581), Staudtstraße 5, 91058 Erlangen

Time: 17.00 p.m. (s.t.) –> Drinks will be served, starting at 16.30 p.m.