Receptor for activated C kinase 1 stimulates nascent polypeptide-dependent translation arrest

Nascent peptide‐dependent translation arrest is crucial for the quality control of eukaryotic gene expression. Here we show that the receptor for activated C kinase 1 (RACK1) participates in nascent peptide‐dependent translation arrest, and that its binding to the 40S subunit is crucial for this. Translation arrest by a nascent peptide results in Dom34/Hbs1‐independent endonucleolytic cleavage of mRNA, and this is stimulated by RACK1. We propose that RACK1 stimulates the translation arrest that is induced by basic amino‐acid sequences that leads to endonucleolytic cleavage of the mRNA, as well as to co‐translational protein degradation. The receptor for activated C kinase (RACK1) participates in nascent peptide sequence‐dependent translation arrest and stimulates the endonucleolytic cleavage of translationally arrested mRNA.