1. The MTR4/hnRNPK complex surveils aberrant polyadenylated RNAs with multiple exons.
- Author
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Taniue K, Sugawara A, Zeng C, Han H, Gao X, Shimoura Y, Ozeki AN, Onoguchi-Mizutani R, Seki M, Suzuki Y, Hamada M, and Akimitsu N
- Subjects
- Humans, HeLa Cells, HEK293 Cells, Exosome Multienzyme Ribonuclease Complex metabolism, Exosome Multienzyme Ribonuclease Complex genetics, Polyadenylation, Nucleocytoplasmic Transport Proteins genetics, Nucleocytoplasmic Transport Proteins metabolism, Introns genetics, RNA Nucleotidyltransferases, Exons genetics, Heterogeneous-Nuclear Ribonucleoprotein K metabolism, Heterogeneous-Nuclear Ribonucleoprotein K genetics, RNA, Messenger genetics, RNA, Messenger metabolism, RNA-Binding Proteins metabolism, RNA-Binding Proteins genetics
- Abstract
RNA surveillance systems degrade aberrant RNAs that result from defective transcriptional termination, splicing, and polyadenylation. Defective RNAs in the nucleus are recognized by RNA-binding proteins and MTR4, and are degraded by the RNA exosome complex. Here, we detect aberrant RNAs in MTR4-depleted cells using long-read direct RNA sequencing and 3' sequencing. MTR4 destabilizes intronic polyadenylated transcripts generated by transcriptional read-through over one or more exons, termed 3' eXtended Transcripts (3XTs). MTR4 also associates with hnRNPK, which recognizes 3XTs with multiple exons. Moreover, the aberrant protein translated from KCTD13 3XT is a target of the hnRNPK-MTR4-RNA exosome pathway and forms aberrant condensates, which we name KCTD13 3eXtended Transcript-derived protein (KeXT) bodies. Our results suggest that RNA surveillance in human cells inhibits the formation of condensates of a defective polyadenylated transcript-derived protein., (© 2024. The Author(s).)
- Published
- 2024
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