This paper introduces the Point Cloud Multipoint Control Unit (PC-MCU): a key component for multi-user holoconferencing systems, where remote participants are represented as Point Clouds. The presented solution redefines the idea of MCU, broadly used to optimize connections and communications between users in traditional videoconferencing, and introduces a set of key features for the optimization of holoconferencing services where multiple users can be remotely connected. The PC-MCU is a virtualized cloud-based component, that aims at reducing the end-user client computational resources and bandwidth usage, providing the following key features: fusion of volumetric videos, Level of Detail (LoD) adjustment and non visible data removal. The results obtained for a scenario with two remote users, show how the introduction of the PC-MCU provides significant benefits in terms of computational resources and bandwidth savings, thus alleviating the requirements at the client side in holoconferencing services when compared to a baseline condition without using it. These improvements open the door to further research on this area to enable scalable and adaptive holoconferencing services using lightweight devices.