ZFIN ID: ZDB-PUB-160713-6
p53-Dependent DNA damage response sensitive to editing-defective tRNA synthetase in zebrafish
Song, Y., Shi, Y., Carland, T.M., Lian, S., Sasaki, T., Schork, N.J., Head, S.R., Kishi, S., Schimmel, P.
Date: 2016
Source: Proceedings of the National Academy of Sciences of the United States of America   113(30): 8460-5 (Journal)
Registered Authors: Kishi, Shuji
Keywords: genomic fidelity, genomic mutations, mistranslation, morphological changes, shortened lifespan
MeSH Terms:
  • Amino Acyl-tRNA Synthetases/genetics
  • Amino Acyl-tRNA Synthetases/metabolism*
  • Animals
  • DNA Damage*
  • Embryo, Nonmammalian/embryology
  • Embryo, Nonmammalian/metabolism
  • Female
  • Gene Expression Regulation, Developmental
  • Male
  • Mutation
  • RNA Editing
  • Tumor Suppressor Protein p53/genetics
  • Tumor Suppressor Protein p53/metabolism*
  • Zebrafish/embryology
  • Zebrafish/genetics
  • Zebrafish/metabolism*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed: 27402763 Full text @ Proc. Natl. Acad. Sci. USA
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ABSTRACT
Brain and heart pathologies are caused by editing defects of transfer RNA (tRNA) synthetases, which preserve genetic code fidelity by removing incorrect amino acids misattached to tRNAs. To extend understanding of the broader impact of synthetase editing reactions on organismal homeostasis, and based on effects in bacteria ostensibly from small amounts of mistranslation of components of the replication apparatus, we investigated the sensitivity to editing of the vertebrate genome. We show here that in zebrafish embryos, transient overexpression of editing-defective valyl-tRNA synthetase (ValRS(ED)) activated DNA break-responsive H2AX and p53-responsive downstream proteins, such as cyclin-dependent kinase (CDK) inhibitor p21, which promotes cell-cycle arrest at DNA damage checkpoints, and Gadd45 and p53R2, with pivotal roles in DNA repair. In contrast, the response of these proteins to expression of ValRS(ED) was abolished in p53-deficient fish. The p53-activated downstream signaling events correlated with suppression of abnormal morphological changes caused by the editing defect and, in adults, reversed a shortened life span (followed for 2 y). Conversely, with normal editing activities, p53-deficient fish have a normal life span and few morphological changes. Whole-fish deep sequencing showed genomic mutations associated with the editing defect. We suggest that the sensitivity of p53 to expression of an editing-defective tRNA synthetase has a critical role in promoting genome integrity and organismal homeostasis.
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