Acknowledgements
The authors acknowledge funding by the Deutsche Forschungsgemeinschaft (Grants PR905/19-1 to GP, GI 312/11-1 to TWG and TE599/9-1 to ST of the DFG priority programme SPP 2225). The authors thank Pietro Alano (Istituto Superiore di Sanità Rome) for providing antisera against G377 and MDV1 and Ron Dzikowski (The Hebrew University of Jerusalem) for providing vector pSLI-HA-glmS. The authors further gratefully acknowledge the microscopy support from the Advanced Light and Fluorescence Microscopy (ALFM) facility at the Centre for Structural Systems Biology (CSSB).