CROWDED MEMBRANES · Macromolecular crowding in membranes
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2007-04-01 → 2009-03-31
- EU contribution
- €184,021
- Participants
- 1
- Scheme
- EIF
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - CROWDED MEMBRANES (Macromolecular crowding in membranes)
The goal of the project was to understand how the presence of high concentration of unrelated membrane proteins influenced the function and interaction of membrane proteins. Many membrane proteins had previously been satisfactorily studied in isolated systems; nevertheless, they faced the background of high concentrations of unrelated proteins in their native environment. As an everyday analogy the experiment on an isolated system could be viewed as a swimmer under competition conditions, where detailed knowledge on swimming technique and absolute performance could be gained. In contrast, the native environment in a living cell was similar, however worse, to a swimming pool on a hot summer day. Clearly, even a well trained swimmer would perform very differently if almost half of the water surface was covered by other swimmers. We therefore tried to establish a controlled environment, where the number and size of obstacles could vary and their influence on the swimmers performance could be studied. The project was hindered by unexpected technical challenges which led to the development of new tools for the analysis of membrane proteins which were either in detergent solubilised state or reconstituted in artificial membranes. One of the developed tools, a novel fluorescent activator of a ligand gated ion channel jump, led to the initiation of a side project so as to better understand the mechanism of a ligand gated ion channel, which is the protein responsible for effective signal transduction from nerve cells to muscle cells.
Data: CORDIS, © European Union
Project objective
The aim of the project is to understand, quantify and model the influence of protein crowding in membranes on molecular mobility and interactions of membrane proteins and ultimately on cellular processes in particular signalling. In cellular membranes proteins occupy almost half of the available surface.Obviously, this high total concentration of macromolecules within the membrane will influence processes in the membrane, even while the concentration of proteins involved in a particular process itself is low. Phenomenological data from animal models showed that signalling kinetics and sensitivity in the visual process, thus likely in G-protein coupled receptor (GPCR) signalling in general is strongly depending on the membrane-protein concentration.However, t he influence of macromolecular crowding on interaction kinetics and equilibria has not been studied experimentally in membranes so far. An in vitro system will be established, in order to monitor how protein-protein interactions in membranes are effected by increasing concentrations of proteins in the membrane. As a read out, state of the art single-molecule fluorescence techniques will be used.Finally, the findings will be related to data obtained in living cells, establishing the relevance of macromolecular crowding in membranes for biological systems and GPCRs specifically.
Original text from CORDIS.
Participants
- ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE · LAUSANNECoordinatorSwitzerland
Links
Data: CORDIS, © European Union