YAE1 is a maturation factor that functions as a target-specific adapter within the LTO1:YAE1 complex, recruiting apolipoprotein-ABCE1 to the cytosolic iron-sulfur (Fe-S) protein assembly (CIA) machinery 1. The complex facilitates Fe-S cluster insertion onto ABCE1 through a coordinated sequence of binding events, where LTO1 engages the CIA targeting complex via its conserved C-terminal tryptophan, and YAE1 recruits the ABCE1 protein 1. This function is evolutionarily conserved, as human YAE1D1 can functionally replace its yeast counterpart 1. YAE1 is required for large ribosomal subunit biogenesis and translation initiation 1, with the YAE1-ABCE1 complex playing critical roles in protecting ribosomes from reactive oxygen species (ROS) damage in aerobic conditions 2. Beyond ribosome biogenesis, the LTO1/YAE1 complex regulates nonsense-mediated mRNA decay (NMD), thereby controlling MHC-I antigen expression in tumor cells 3. YAE1 is frequently upregulated in hepatocellular carcinoma and other human malignancies [PMID:41502527; 44], suggesting its overexpression may contribute to cancer development through enhanced ROS protection and altered antigen presentation.