Recently, it has been suggested that BNC2 is also involved in mRNA export, nonsense-mediated decay, and/or polyadenylation [ 61].
Importantly, shuttling SR proteins have been shown to participate in a wide range of post-splicing activities, including mRNA nuclear export, nonsense-mediated mRNA decay, and mRNA translation (reviewed by Long and Caceres, 2009 and Twyffels et al., 2011).
Splicing-dependent deposition of the EJC plays a profound role in mRNA metabolism, regulating nuclear export, nonsense-mediated decay, efficiency of translation, and RNA localization (Hachet and Ephrussi 2004; Ghosh et al. 2012, 2014; Popp and Maquat 2014).
Interestingly, a proteomic analysis of the Arabidopsis nucleolus revealed that many proteins involved in pre-mRNA splicing, including some SR proteins, some snRNP proteins (i.e. SF3b49, U2A', SART3, SmD1-D3, G, F), as well as exon-junction complex proteins, which are involved in mRNA export and nonsense mediated decay, localise to some extent to this nuclear compartment [56].
Interestingly, the RNA-binding protein RBM8A, known to be required for mRNA metabolic processes such as splicing, mRNA export and nonsense-mediated mRNA decay, is localized to the centrosome and nuclei [ 33].
Moreover, the interactions between the spliceosome and proteins responsible for transcription, capping, polyadenylation, RNA export, and nonsense-mediated mRNA decay (Maniatis and Reed 2002) support an integral role for introns in affecting transcriptional and translational yield (Juneau et al. 2006).
He believes the whole "exporting water" argument is nonsense - that all agricultural exports contain water - and that there are few better uses for it.
"You can't reduce the surplus by reducing exports, that would be nonsense," said Christian Dreger, an economist at the German Institute for Economic Research in Berlin.
China's price deflation and the dollar's weakness mean that the yuan is actually depreciating in real terms (though it is nonsense to accuse China of exporting deflation: its cheap exports are changing relative prices, not generating deflation overall).
The majority of the stable SUTs appear to be processed by the regular CPF/polyadenylation pathway, exported and finally degraded by the cytoplasmic nonsense mediated RNA decay pathway [137].
For example, the involvement of the nucleolus in mRNP biogenesis has been studied extensively in plants, where the nucleolus has key functions in nonsense-mediated decay and mRNA export (Brown and Shaw, 2008).
