Inactivation of organellar glutamyl- and seryl-tRNA synthetases leads to developmental arrest of chloroplasts and mitochondria in higher plants

Yu Kyung Kim, Jae Yong Lee, Hye Sun Cho, Sang Sook Lee, Hyun Jung Ha, Sunghoon Kim, Doil Choi, Hyun Sook Pai

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)

Abstract

Aminoacyl-tRNA synthetases (ARSs) are key enzymes involved in protein translation, and both cytosolic and organellar forms are present in the genomes of eukaryotes. In this study, we investigated cellular effects of depletion of organellar forms of ARS using virus-induced gene silencing (VIGS) in Nicotiana benthamiana. VIGS of NbERS and NbSRS, which encode organellar GluRS and SerRS, respectively, resulted in a severe leaf-yellowing phenotype. The NbERS and NbSRS genes were ubiquitously expressed in plant tissues, and induced in response to light. Green fluorescent protein (GFP) fusion proteins of the full-length glutamyl-tRNA synthetase (ERS) and seryl-tRNA synthetase (SRS) of Arabidopsis and GFP fusions to the N-terminal extension of these proteins were all dual-targeted to chloroplasts and mitochondria. At the cell level, depletion of NbERS and NbSRS resulted in dramatically reduced numbers of chloroplasts with reduced sizes and chlorophyll content. The numbers and/or physiology of mitochondria were also severely affected. The abnormal chloroplasts lacked most of the thylakoid membranes and appeared to be degenerating, whereas some of them showed doublet morphology, indicating defective chloroplast division. Pulse-field gel electrophoresis analyses demonstrated that chloroplast DNA in subgenomic sizes is the predominant form in the abnormal chloroplasts. Interestingly, despite severe abnormalities in chloroplasts and mitochondria, expression of many nuclear genes encoding chloroplast- or mitochondria-targeted proteins, and chlorophyll biosynthesis genes remained unchanged in the ERS and SRS VIGS lines. This is the first report to analyze the effect of ARS disruption on organelle development in plants.

Original languageEnglish
Pages (from-to)37098-37106
Number of pages9
JournalJournal of Biological Chemistry
Volume280
Issue number44
DOIs
Publication statusPublished - 2005 Nov 4

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint

Dive into the research topics of 'Inactivation of organellar glutamyl- and seryl-tRNA synthetases leads to developmental arrest of chloroplasts and mitochondria in higher plants'. Together they form a unique fingerprint.

Cite this