Biophysical Society Thematic Meeting | Ascona, Switzerland

Liposomes, Exosomes, and Virosomes: From Modeling Complex Membrane Processes to Medical Diagnostics and Drug Delivery

Thursday Speaker Abstracts

Stress-dependent Prion-like Aggregate Formation Regulates Protein Sorting and Export at the Trans-Golgi Network Claudia Stohrer, Martina Horanova, Anne Spang . Organisms have to respond to environmental stress such as dehydration. To mount a rapid response, sensors are present in the plasma membrane serving as a signal relay station. Polycystin2 (PKD2)-related TRP channels act as mechanosensors and are activated under hypotonic conditions. The yeast PKD2-related Flc2 is present at the plasma membrane and the ER. The localization of the protein is dependent on the presence of functional ER-plasma membrane contact sites and constant cycling between the trans-Golgi Network (TGN) and the plasma membrane. Regulated export of Flc2 to the plasma membrane is achieved by the exomer adaptor complex. While Flc2 is plasma membrane-localized in iso- and hypotonic medium, it is rapidly endocytosed and stored in the TGN under hyperosmotic stress. Flc2 contains a short N- rich unstructured stretch in the C-terminus, and TGN retention is at least partly dependent on the prion-like domain of Pin2. This prion-like domain dependent retention mechanism prevents untimely discharge of the proteins at the plasma membrane and equally protects it form degradation. Upon stress removal, Flc2, similar to Pin2, quickly regained plasma membrane localization, in a process involving the Batten disease protein Btn2, which has been implicated in resolving prion aggregates. Thus Pin2 and Flc2 might be part of a stress-stabilized liquid droplet domain at the TGN that is resolved by Btn2 when the stress subsides.

The Role of Cholesterol in Virus Entry

Lukas Tamm University of Virginia, Charlottesville, VA, USA

No Abstract

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