The nuclear RNA surveillance machinery: The link between ncRNAs and genome structure in budding yeast?

The TRAMP polyadenylation complexes have well-established functions in RNA surveillance, stimulating degradation by the 3′ to 5′ exonuclease activity of the exosome on a wide range of nuclear RNAs and RNA-protein complexes. Known targets include some of the non-protein coding RNA transcripts (ncRNAs), which are apparently widely transcribed from yeast and mammalian genomes. We will discuss potential mechanisms of TRAMP recruitment and exosome activation during RNA surveillance and degradation. Less well-understood observations link both the TRAMP and exosome complexes to chromatin structure and DNA repair, and we will speculate on the potential significance of these activities.