We offer 1 fully funded PhD position with immediate effect located at the Institute of Cell Biology, Biocenter, Medical University of Innsbruck and supervised by Ass.-Prof. Georg-Friedrich Vogel (Cell Biology, Paediatrics I). The project is embedded within the PhD program Cellular Basis of Diseases (CBD) at the Medical University of Innsbruck, Austria. This interdisciplinary PhD program addresses the molecular control of metabolism & inflammation and connect basic life science and computational biology with medicine.

To read more about the program and the requirements, please use the following link: https://phd-cbdiseases.i-med.ac.at/
Project: The role of ER-PM contact sites in epithelial polarity

In a CRISPR/Cas9 KO screen on apical trafficking in epithelial cells, our group has identified two candidate genes involved in endoplasmic reticulum (ER) - plasma membrane (PM) contact sites (EPCS) formation and function: anoctamin 8 (ANO8) and transmembrane protein 110 (TMEM110). EPCS have various physiological functions, such as intracellular as well as ER Ca2+ homeostasis and regulation of phosphatidylinositolphosphate (PIP) at the PM.
ANO8 was shown to be recruited to EPCS in a PI(4,5)P2-dependent manner and replenishes Ca2+ storage by recruiting the Sarco/endoplasmatic reticulum Ca2+-ATPase. TMEM110 is known to activate and enhance another ER-PM-protein STIM1, hence is also termed STIM-activating enhancer (STIMATE). STIM1-TMEM110 interaction is crucial for Ca2+ influx at the plasma membrane upon exhaustion of Ca2+ storage and TMEM110 knockdown reduces STIM1 localization at the PM.
However, little to nothing is known about their role in formation or turnover of the apical domain in epithelial cells and polarized epithelial tissues. Interestingly, preliminary descriptive work suggests an exclusion of contact sites from the apical PM in hepatocytes. Work in fission yeast concludes that EPCS restrict sites of polarized exocytosis and that high Cdc42 activity in regions of exocytosis, typically the apical PM in higher eukaryotes, permit the formation of EPCS.

This project aims to understand the involvement of ANO8 and TMEM110 in the establishment of epithelial polarity and proper apical trafficking of cargo proteins. Therefore, epithelial cell models will be used, such as 3D MDCK cyst cultures. Main techniques for this project include CRISPR/Cas9 mediated genome editing, 3D cyst cultures, apical trafficking assays, proteinprotein interaction studies, and immunofluorescence and electron microscopy. Experience in epithelial cell culture, genome editing, immunofluorescence microscopy and protein biochemistry are beneficial.

Contact:
georg.vogel@i-med.ac.at