PMC:2728203 / 3041-4614 JSONTXT

{"project":"2_test","denotations":[{"id":"18190927-17786152-62517956","span":{"begin":388,"end":390},"obj":"17786152"},{"id":"18190927-15933735-62517956","span":{"begin":388,"end":390},"obj":"15933735"},{"id":"18190927-12787776-62517956","span":{"begin":388,"end":390},"obj":"12787776"},{"id":"18190927-11849973-62517957","span":{"begin":537,"end":539},"obj":"11849973"},{"id":"18190927-17352659-62517958","span":{"begin":738,"end":740},"obj":"17352659"},{"id":"18190927-12210514-62517959","span":{"begin":822,"end":824},"obj":"12210514"},{"id":"18190927-17786152-62517960","span":{"begin":1140,"end":1142},"obj":"17786152"},{"id":"18190927-15933735-62517960","span":{"begin":1140,"end":1142},"obj":"15933735"},{"id":"18190927-15137937-62517960","span":{"begin":1140,"end":1142},"obj":"15137937"},{"id":"18190927-14718167-62517960","span":{"begin":1140,"end":1142},"obj":"14718167"},{"id":"18190927-10085285-62517961","span":{"begin":1367,"end":1369},"obj":"10085285"},{"id":"18190927-14718167-62517962","span":{"begin":1571,"end":1573},"obj":"14718167"}],"text":"Cells require an efficient mechanism to establish when mRNA is mature and competent for export. Thus, there are a number of cellular quality-control mechanisms that work actively to destroy improperly processed transcripts and preferentially export correctly processed mRNA to complement the cellular factors that assure coordinated production and export of correct mRNA transcripts.2,10,11 The nuclear exosome, a complex of 3′–5′ riboexonucleases, can detect and destroy aberrant or incorrectly processed transcripts within the nucleus.12 Several additional quality-control mechanisms function posttranscriptionally and include the nonsense-mediated decay pathway, which recognizes transcripts with defects such as premature stop codons,13 and the nonstop decay pathway, which recognizes transcripts lacking a stop codon.14 Recognition of transcripts by any of these pathways leads to their destruction. In addition to these “search-and-destroy” quality-control mechanisms in the nucleus and the cytoplasm, recent work has uncovered evidence in Saccharomyces cerevisiae that surveillance of mRNA can also occur at the nuclear pore.2,10,15,16 These studies suggest that specific interactions between mRNA-binding proteins associated with a given transcript and the evolutionarily conserved myosin-like protein 1 (Mlp1), located at the inner nuclear basket of the NPC,17 can influence nuclear export of that transcript. For example, if introns are retained in a transcript, interactions between splicing factors and Mlp1 lead to retention of the transcript in the nucleus.16"}