RESUMO
A significant proportion of RNA decay in eukaryotes takes place in the nucleus. In addition to targeting nongenic RNAs such as products of processing and spurious transcription events, nuclear RNA decay also removes aberrant transcripts from regular genes. Moreover, a small list of genes utilizes nuclear RNA turnover to regulate their expression levels. This chapter highlights concepts and techniques used in our laboratory to estimate nuclear mRNA degradation in Saccharomyces cerevisiae. This chapter focuses on the nuclear RNA decay route of the heat-inducible HSP104 transcript in strains harboring an inactive THO/Sub2p mRNA export complex. The described approaches are readily adoptable to the analysis of other cases of nuclear mRNA degradation.