Project B3 aims to investigate the modes of proteasome biogenesis, which are important to form different functional multi-subunit proteasome modules in mammalian cells. In the next grant period this project will proceed with the in vitro and in vivo analyses of proteasome assembly steps including determinants of translational control of proteasomes. Furthermore, the project will extend the studies on structure and function relationships using the different proteasome mutations found in patients and in terms of association of regulator particles on the proteasome core complex.