PROTEASOMES (PROSOMES) INHIBIT THE TRANSLATION OF TOBACCO-MOSAIC-VIRUS RNA BY PREVENTING THE FORMATION OF INITIATION-COMPLEXES

Proteasomes (prosomes) are large multiprotein complexes. They are invo lved in protein degradation of ubiquitin conjugated proteins and in th e generation of MHC class I peptides. We gave further evidence that th ey interfere with in vitro protein synthesis. Proteasomes inhibit the translation of Tobacco mosaic virus RNA. Analysis of cell-free systems by sucrose gradient centrifugation revealed that they prevent the for mation of 80S initiation complexes but not the early phase of initiati on.