Fig. 2

Diverse pathways governing mRNA decay. A Various RNA binding proteins (RBPs) like TTP, Roquin, and the YTHDF family, along with stalled translating ribosomes, initiate mRNA decay pathways by recruiting the deadenylase complex. This results in poly(A) tail shortening, enabling access for the cytoplasmic RNA exosome complex to undertake 3′-5′ exonucleolytic decay. Additionally, decapping exposes 5′ ends, targeted by XRN1 for 5′-3′ exonucleolytic decay. B An alternative pathway, endonucleolytic mRNA decay, is initiated by endonucleases such as the Regnase family. Regnase-1-mediated mRNA decay requires active translation and the RNA helicase UPF1