mTOR regulates the nucleoplasmic diffusion of Xrn2 under conditions of heat stress

• Published in: FEBS letters Vol. 588; no. 18; pp. 3454 - 3460
• Main Authors: Watanabe, Kazunori, Ijiri, Kenichi, Ohtsuki, Takashi
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 17.09.2014
• Subjects: Cell Nucleolus - metabolism; Exoribonucleases - metabolism; Gene Expression Regulation; Heat stress; Heat-Shock Response; HeLa Cells; Humans; Mammalian target of rapamycin; Protein Biosynthesis; Protein Transport; RNA Stability; RNA, Transfer, Met - genetics; RNA, Transfer, Met - metabolism; TOR Serine-Threonine Kinases - physiology; tRNA degradation; Xrn2; Heat stress; tRNA degradation; Mammalian target of rapamycin; Xrn2
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2014.08.003

•Heat stress induces the diffusion of Xrn2 into the nucleoplasm.•mTOR regulates the diffusion of Xrn2 into the nucleoplasm.•mTOR regulates the degradation of initiator tRNAMet. Stress induces various responses, including translational suppression and tRNA degradation in mammals. Previously, we showed that heat stress induces degradation of initiator tRNAMet (iMet) through 5′–3′ exoribonuclease Xrn1 and Xrn2, respectively. In addition, we found that rapamycin inhibits the degradation of iMet under heat stress conditions. Here, we report that the mammalian target of rapamycin (mTOR) regulates the diffusion of Xrn2 from the nucleolus to the nucleoplasm, facilitating the degradation of iMet under conditions of heat stress. Our results suggest a mechanism of translational suppression through mTOR-regulated iMet degradation in mammalian cells.