RanBP2/Nup358 Potentiates the Translation of a Subset of mRNAs Encoding Secretory Proteins

In higher eukaryotes,most mrnas that encode secreted or membrane-bound proteins contain elements that promote an alternative mrna nuclear export (alrex) pathway. here we report that alrex-promoting elements also potentiate translation in the presence of upstream nuclear factors. these rna elements interact directly with,and likely co-evolved with,the zinc finger repeats of ranbp2/nup358,which is present on the cytoplasmic face of the nuclear pore. finally we show that ranbp2/nup358 is not only required for the stimulation of translation by alrex-promoting elements,but is also required for the efficient global synthesis of proteins targeted to the endoplasmic reticulum (er) and likely the mitochondria. thus upon the completion of export,mrnas containing alrex-elements likely interact with ranbp2/nup358,and this step is required for the efficient translation of these mrnas in the cytoplasm. alrex-elements thus act as nucleotide platforms to coordinate various steps of post-transcriptional regulation for the majority of mrnas that encode secreted proteins. © 2013 mahadevan et al.