1. Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim/Ruhr, Germany, Institute of Pharmacology and Toxicology, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland, Department of Cell and Molecular Biology, Uppsala University, Box 596, Biomedical Center, S-75124 Uppsala, Sweden, University Paul-Cézanne/Faculté Sciences et Techniques de St Jérome, case 432 Avenue Escadrille Normandie Niemen, 13397 Marseille Cedex 20, France, and Department of Molecular...