1. Department of Biology II, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
2. Center for Integrated Protein Science Munich, 81377 Munich, Germany
3. Department of Gene Expression, Helmholtz Zentrum Munich-German Research Center for Environmental Health, 81377 Munich, Germany
4. Faculty of Medicine, Institute for Molecular Tumor Biology, Westphalian Wilhelms University Muenster, 48149 Muenster, Germany
5. Department of Biology, Technische Universität Darmstadt, 64289 Darmstadt, Germany