Staufen-mediated mRNA decay

Staufen1 ( STAU1 )‐mediated mRNA decay ( SMD ) is an mRNA degradation process in mammalian cells that is mediated by the binding of STAU1 to a STAU1 ‐binding site ( SBS ) within the 3′‐untranslated region (3′‐ UTR ) of target mRNAs . During SMD , STAU1 , a double‐stranded (ds) RNA ‐binding protein, recognizes dsRNA structures formed either by intramolecular base pairing of 3′‐ UTR sequences or by intermolecular base pairing of 3′‐ UTR sequences with a long‐noncoding RNA ( lncRNA ) via partially complementary Alu elements. Recently, STAU2 , a paralog of STAU1 , has also been reported to mediate SMD . Both STAU1 and STAU2 interact directly with the ATP ‐dependent RNA helicase UPF1 , a key SMD factor, enhancing its helicase activity to promote effective SMD . Moreover, STAU1 and STAU2 form homodimeric and heterodimeric interactions via domain‐swapping. Because both SMD and the mechanistically related nonsense‐mediated mRNA decay ( NMD ) employ UPF1 ; SMD and NMD are competitive pathways. Competition contributes to cellular differentiation processes, such as myogenesis and adipogenesis, placing SMD at the heart of various physiologically important mechanisms. WIREs RNA 2013, 4:423–435. doi: 10.1002/wrna.1168 This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms