Abstract:
Staufen (STAU) is a double-stranded RNA binding protein. STAU-mediated mRNA decay (SMD), which occurs when translation terminates sufficiently upstream of a STAU-binding site (SBS), is important to developmental and homeostatic pathways1. An SBS can be created by intramolecular base-pairing within an mRNA 3'-untranslated region (3'UTR) or by intermolecular base-pairing between a 3'UTR and one or more long noncoding RNAs. Intermolecular base-pairing in humans involves Alu elements4, which are a type of small interspersed repetitive element (SINE), whereas intermolecular base-pairing in rodents involves B and identifier SINEs3. Roles of STAU1 dimerization4 and the STAU1 paralog STAU25 in SMD will be discussed. A mechanism by which mRNAs crosstalk in a way that involves direct mRNA−mRNA interactions between 3'UTR Alu elements in each mRNA will be described, uncovering a new role for mammalian-cell mRNAs6. This unexpected function, together with our discovering how STAU1 binding to inverted-repeated 3'UTR Alu elements (IRAlus) competes with nuclear retention mediated by p54nrb binding to 3'UTR IRAlus and also the repression of cytoplasmic translation mediated by PKR binding to 3'UTR IRAlus7, adds new layers of complexity to the network of post-transcriptional interactions that regulate gene expression and involve noncoding RNAs.
1Park E, Maquat LE (2013) WIRES RNA 4:423-35.
2Gong C, Maquat LE (2011) Nature 470: 284-8.
3Wang J, Gong C, Maquat LE (2013) Genes Dev 27: 793-804.
4Gleghorn ML, Gong C, Kielkopf CL, Maquat LE (2013) NSMB 20:515-24.
5Park E, Gleghorn ML, Maquat LE (2013) PNAS 110: 405-12.
6Gong, C., Tang, Y. and Maquat, L.E. (2013) NSMB 20:1214-20.
7Elbarbary, R., Li, W., Tian, B. and Maquat, L.E. (2013) Genes Dev 27:1495-1510.