Switch function of proteins
Projektleiter: Prof. Dr. Karl-Wilhelm Koch
Kooperationspartner: Prof. Dr. Jens Christoffers, Prof. Dr. Christoph Lienau, Prof. Dr. Walter Neu
Rod photoreceptor cells are very energy efficient systems, which detect photons with high precision and time-resolution and transform these primary signaling events into a cellular response. Fine-tuned protein-protein interactions that are triggered by specific molecular switches are involved in these cellular responses. Switch mechanisms will be investigated in the proposed PhD project on biological membranes (resembling cellular membranes) or on artificial surfaces. One class of proteins named neuronal calcium sensor (NCS) proteins will be in the focus of the envisioned research, since these proteins operate as switching molecules. They are often covalently acylated (mainly myristoylated), which in some proteins play an important regulatory role. In order to detect conformational changes in NCS proteins fluorescence dyes will be attached to NCS proteins allowing intramolecular FRET measurements. The association of proteins with membranes will be investigated with surface plasmon resonance using immobilized lipid surfaces on sensor chips. In addition, interaction of labelled proteins will be measured by isothermal titration calorimetry (ITC). Intracellular protein translocation will be investigated in cell culture systems that had been transfected with fluorescence-labelled NCS proteins. The research project is aimed at deepening our molecular understanding of energy efficient signaling pathways in cells.