The ASC-1 Complex Disassembles Collided Ribosomes

• DOI: 10.1016/j.molcel.2020.06.006
• Publication Date: 2020-06-23T14:34:32Z
• Authors: Szymon Juszkiewicz; Shaun H. Speldewinde; Li Wan; Jesper Q. Svejstrup; Ramanujan S. Hegde
• Keywords: Polysome; Ribosomal protein; Ribosome profiling; Eukaryotic Ribosome

Translating ribosomes that slow excessively incur collisions with trailing ribosomes. Persistent are detected by ZNF598, a ubiquitin ligase ubiquitinates sites on the ribosomal 40S subunit to initiate pathways of mRNA and protein quality control. The collided ribosome complex must be disassembled downstream control, but mechanistic basis disassembly is unclear. Here, we reconstitute polysome in mammalian cell-free system. widely conserved ASC-1 (ASCC) containing ASCC3 helicase disassembles leading an ATP-dependent reaction. Disassembly, not association, requires ubiquitination GTP-dependent factors, including Pelo-Hbs1L rescue complex. Trailing can elongate once roadblock has been removed only become targets if they subsequently stall collisions. These findings define specific role ASCC during ribosome-associated control identify molecular target its activity.