Putative model of the decay of mislocalized mRNAs. Once entering the cytoplasm, mRNAs that are bound for a specific subcellular location are initially translationally repressed and are subject to deadenylation. If localization proceeds faster than decay (left), the mRNA will be properly localized and enter into translation. Canonical decay processes will then degrade the mRNA. However, if there is a localization defect, which manifests in accelerated decay of the mRNA (right), the mRNA will be degraded before reaching its final destination. Gray, blue, and green features represent RNA-binding proteins (RBPs) bound to mRNAs before localization. Cellular nucleases are shown as red “pacman” figures.