Nuclear export of mRNA and its regulation by ubiquitylation.

The export of mRNA from nucleus to cytoplasm is a key regulatory step in the expression of RNA polymerase II genes in eukaryotes, and thus, a variety of human diseases are manifested by abnormal mRNA export. Therefore, a large number of studies over many years have been directed towards elucidating the regulatory mechanisms of mRNA export. These studies have identified several mRNA export-associated factors and delineated their regulatory networks. Intriguingly, mRNA export has also been shown to be regulated by ubiquitylation, a post-translational modification that targets proteins for degradation or transport and has been linked to different cellular processes such as cell cycle progression, DNA repair, transcription and intracellular trafficking. While the mechanisms of actions of ubiquitylation in different cellular processes are relatively well-established, it is not clearly understood how mRNA export is regulated by ubiquitylation. Here, we highlight the recent advances of mRNA export and its regulation by ubiquitylation or the enzymes controlling this posttranslational modification.