Format

Send to

Choose Destination
See comment in PubMed Commons below
Nucleic Acids Res. 2013 Apr;41(8):4671-85. doi: 10.1093/nar/gkt153. Epub 2013 Mar 6.

Degradation of initiator tRNAMet by Xrn1/2 via its accumulation in the nucleus of heat-treated HeLa cells.

Author information

1
Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan. watanabe@ric.u-tokyo.ac.jp

Abstract

Stress response mechanisms that modulate the dynamics of tRNA degradation and accumulation from the cytoplasm to the nucleus have been studied in yeast, the rat hepatoma and human cells. In the current study, we investigated tRNA degradation and accumulation in HeLa cells under various forms of stress. We found that initiator tRNA(Met) (tRNA(iMet)) was specifically degraded under heat stress. Two exonucleases, Xrn1 and Xrn2, are involved in the degradation of tRNA(iMet) in the cytoplasm and the nucleus, respectively. In addition to degradation, we observed accumulation of tRNA(iMet) in the nucleus. We also found that the mammalian target of rapamycin (mTOR), which regulates tRNA trafficking in yeast, is partially phosphorylated at Ser2448 in the presence of rapamycin and/or during heat stress. Our results suggest phosphorylation of mTOR may correlate with accumulation of tRNA(iMet) in heat-treated HeLa cells.

PMID:
23471000
PMCID:
PMC3632136
DOI:
10.1093/nar/gkt153
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Silverchair Information Systems Icon for PubMed Central
    Loading ...
    Support Center