E3 ubiquitin-protein ligase component of the ribosome quality control complex (RQC), a ribosome-associated complex that mediates ubiquitination and extraction of incompletely synthesized nascent chains for proteasomal degradation (PubMed:23685075, PubMed:25132172, PubMed:25578875, PubMed:28757607). Within the RQC complex, LTN1 is recruited to stalled 60S ribosomal subunits by NEMF and mediates ubiquitination of stalled nascent chains (PubMed:25578875). Ubiquitination leads to VCP/p97 recruitment for extraction and degradation of the incomplete translation product (By similarity).