1. Institute of Biochemistry I, University of Regensburg, Universitaetsstrasse 31, D-93053 Regensburg, Germany
2. Institute of Zoology, University of Regensburg, Universitaetsstrasse 31, D-93053 Regensburg, Germany
3. Institute of Biochemistry, Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 17, D-35392 Giessen, Germany
4. Institute for Molecular and Cellular Anatomy, University of Regensburg, Universitaetsstrasse 31, D-93053 Regensburg, Germany
5. Medical Clinic D, University of Muenster, Domagkstrasse 3, D-48149 Muenster, Germany