In this perspective, we discuss the regulatory impact of nuclear RNA export and decay on messenger RNA (mRNA) functionality. It is well established that control of protein-coding gene expression in eukaryotes employs the regulated production of mRNA, its intra-cellular transfer to cytoplasmic ribosomes and final transcript degradation. Despite a rich body of literature on these events, an involvement of nuclear RNA decay systems remains largely unexplored. Instead, nuclear RNA degradation is often considered a quality control precaution engaged primarily in ridding cells of aberrantly processed transcripts and spurious non-coding RNA. Recent research from human and budding yeast cells, however, demonstrates that even protein-coding transcripts fall prey to nuclear decay and that this is countered by their nuclear export. Here, we outline the potential of nuclear polyA-binding proteins in tuning levels of cellular mRNA to maintain transcript homeostasis.
Keywords: Nab2; Nuclear RNA degradation; Nuclear RNA export; PABPN1; Transcription termination.