The yin and yang of the exosome.
Recent studies of the eukaryotic ribosomal RNA processing pathway have identified 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. How the cell regulates the nucleolytic prowess of the exosome to ensure correct and timely synthesis and destruction of RNAs is a central focus of current research.
Butler
J Scott
JS
Dept of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Box 672 601, Elmwood Ave, Rochester, NY 14642, USA. btlr@mail.rochester.edu
D000818:Animals; D005095:Exoribonucleases / Q000378:metabolism*; D006801:Humans; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000378:metabolism; D020537:RNA, Small Nucleolar / Q000378:metabolism
D012333:RNA, Messenger; D012335:RNA, Ribosomal; D012342:RNA, Small Nuclear; D020537:RNA, Small Nucleolar; D005095:Exoribonucleases