exosome
In the eukaryotic ribosomal RNA processing pathway, a complex of ten riboexonucleases called the exosome that plays a central role in the precise formation of the 3? ends of several types of RNAs.
The exosome also destroys excess ribosomal RNA precursors and unused intermediates and degrades poly(A)-mRNAs in the cytoplasm.
In the nucleus, the complex appears to function in a regulated mRNA surveillance system that degrades transcripts in response to defects in the mRNA processing and export pathways.
The exosome complex of 3??>5? exonucleases is an important component of the RNA-processing machinery in eukaryotes. This complex functions in the accurate processing of nuclear RNA precursors and in the degradation of RNAs in both the nucleus and the cytoplasm.
References
Houseley J, LaCava J, Tollervey D. RNA-quality control by the exosome. Nat Rev Mol Cell Biol. 2006 Jul;7(7):529-39. PMID: 16829983
Butler JS. The yin and yang of the exosome. Trends Cell Biol. 2002 Feb;12(2):90-6. PMID: 11849973