RNA-binding protein Staufen2 is required for dendritic spine morphogenesis

Local translation of certain mRNAs at synapses in response to activation critically contributes to asymmetric cell polarity and synaptic plasticity (Kiebler and DesGroseillers, 2000; Steward and Schuman, 2001; St Johnston, 2005). The double-stranded RNA-binding protein Staufen has been implicated both in dendritic RNA transport and translational regulation (Tang et al., 2001; Kim et al., 2005). In Drosophila, Staufen (Stau) is required for both bicoid and oskar mRNA localization in the oocyte (St Johnston, 2005) and for the localization of prospero mRNA in embryonic neuroblasts (Li et al., 1997; Broadus et al., 1998). In Xenopus, two Staufen isoforms (XStau1 and XStau2) are present in the oocytes and move to the vegetal cytoplasm, where both VegT and Vg1 mRNAs become localized (Allison et al., 2004; Yoon and Mowry, 2004). In mammals, Stau1 and 2 proteins are implicated in the microtubule-dependent transport of RNAs to dendrites of polarized neurons (Kiebler et al., 1999; Tang et al., 2001). Both Stau proteins are present in