Previous work of our group investigated the role of the proteins Anakonda (Byri et al., 2015) and M6 (Wittek et. al., 2020, in revision) in establishing tricellular septate junctions (tSJ) in epithelial tissues in Drosophila melanogaster and their impact on sealing the epithelium thereby preventing para-cellular diffusion. In my project I will build on top of this work and try to decipher the molecular interactions between proteins that form the tSJ. The primary aim of my PhD thesis is to gain further insights into the composition and assembly of the hypothesized complex that seals epithelial cells at tricellular septate junctions in D. melanogaster. To address this question, I will make use of biochemical, genetic, and microscopy-based approaches in embryos and cultured cells.
- The first step is to test for the interaction between M6 and Aka.
- Second, I will investigate the roles of the different isoforms of M6 and to identify those isoform(s) that are localize to tricellular junctions and are required for their formation.
- Third, I will characterize post-translational modifications of M6 and other tSJ proteins, focusing on palmitoylation of the cytosolic domains of these proteins.
- Byri, S., Misra, T., Syed, Z.A., Bätz, T., Shah, J., Boril, L., Glashauser, J., Aegerter-Wilmsen, T., Matzat, T., Moussian, B., et al. (2015). The Triple-Repeat Protein Anakonda Controls Epithelial Tricellular Junction Formation in Drosophila. Developmental Cell 33, 535–548.