Upf1 also known as Rent1, HUPF1 is a protein that is part of a post-splicing multiprotein complex involved in both mRNA nuclear export and mRNA surveillance. Upf1 plays a crucial role in nonsense-mediated RNA decay (NMD), which maintains cellular integrity by preventing translation of defective mRNA transcripts that could produce truncated or harmful proteins. This mechanism is particularly important in eukaryotic cells, where detecting and degrading such transcripts helps protect organisms from potential deleterious effects. Rent1, a mammalian ortholog of Upflp, is essential for embryonic viability and features a complex structure including an N-terminal zinc finger-like domain and NTPase domains, classifying Rent1 as a member of the superfamily group I helicase.