1. Department of Protein Technology, Lund University, Sölvegatan 33, Wallenberglaboratoriet, SE-221 00 Lund, Sweden, Department of Biophysical Chemistry, Lund University, SE-221 00 Lund, Sweden, and Department of Cell and Molecular Biology, Section for Molecular Signaling, Lund University, SE-22184 Lund, Sweden