About the illustration

This illustration visualizes how RIOK3 mediates 40S ribosomal subunit degradation during cellular stress, specifically in response to cellular starvation.

When the 40S subunit is ubiquitylated, RIOK3—a kinase—recognizes the attached ubiquitin and binds to the subunit. This interaction displaces part of the ribosome and exposes the 3′ end of the 18S rRNA. The exposed rRNA is then accessible to a 3′-5′ exonuclease, which degrades it into smaller fragments. These fragments are subsequently targeted by the proteasome for protein degradation.

Created in collaboration with Dr. Rachel Green and the Green Lab at Johns Hopkins School of Medicine, this illustration serves as a visual aid for researchers and content experts to communicate a key mechanism in ribosomal quality control during stress responses.