Functionality controlled by organization in and between membranes

1. funding period 01/2009-12/2012
2. funding period 01/2013-12/2016
3. funding period 01/2017-03/2021

It is the aim of the Sonderforschungsbereich 803 (Collaborative Research Center, SFB 803) to unravel the interactions between the large number of different lipids and specialized proteins in cellular membranes on the molecular level. We seek to clarify how the spatial and temporal organization of membrane components influences their function. Within this general and highly active research field, the SFB 803 has focused on two major themes: A) Organization and function of peptides and proteins in lipid membranes and B) Molecular structures associated with membrane-membrane interactions. The expected result of the SFB 803 is to obtain molecular pictures of how peptides and proteins in the lipid membrane as well as between two membranes form structures that are responsible for transport processes across membranes and the fusion of two lipid bilayers.
The results obtained in the first two funding periods put the SFB 803 now in an ideal position to address the questions of how peptide and protein-mediated transport of small molecules and ions across membranes is achieved and how the overall membrane organization as well as specific lipid-protein-interactions alter transport properties of peptide assemblies and proteins. The expected results will provide us with a detailed understanding of the function of non-covalent peptide assemblies and transmembrane proteins such as mechanosensitive and voltage-gated channels in the context of transport phenomena across membranes. Moreover, this part of the research program forms a bridge to the second major aim of the SFB by contributing to our understanding how transmembrane helices are involved in and facilitate membrane fusion. In this regard, the SFB 803 aims to understand how physical mesoscopic parameters such as membrane curvature and lateral tension as well as molecular determinants such as particular lipids and the molecular structure of different SNAREs (soluble N-ethylmaleimide-sensitive-factor attachment receptors) determine and influence the energy landscape along the fusion pathway. We expect to obtain a unified picture of the fusion mechanism and to understand how regulatory proteins influence this process on the molecular level.



funded by the Deutsche Forschungsgemeinschaft