1. Department of Chemistry and Pharmacy, Albert-Ludwigs University Freiburg, Albertstrasse 21, 79104 Freiburg i.B., Germany
2. Cell Biology & Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
3. Department of Chemical Physiology and Biochemistry, Oregon Health & Science University (OHSU), Sam Jackson Park Road, Portland, Oregon 97239-3098, United States
4. CIBSS—Centre for Integrative Biological Signalling Studies, 79104 Freiburg i.B., Germany
5. Freiburg Research Institute for Advanced Studies (FRIAS), Albert-Ludwigs University Freiburg, Albertstrasse 19, 79104 Freiburg i.B., Germany