Localization of eIF4A-III in the nucleolus and splicing speckles is an indicator of plant stress
Koroleva, O., Brown, J. and Shaw, P. (2009) Localization of eIF4A-III in the nucleolus and splicing speckles is an indicator of plant stress. Plant Signaling & Behavior, 4 (12). pp. 1148-1151. ISSN 1559-2316
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To link to this article DOI: 10.4161/psb.4.12.9906
The mechanisms of long-term adaptation to low oxygen environment are quite well studied, but little is known about the sensing of oxygen shortage, the signal transduction and the short-term effects of hypoxia in plant cells. We have found that an RNA helicase eIF4A-III, a putative component of the Exon Junction Complex, rapidly changes its pattern of localisation in the plant nucleus under hypoxic conditions. In normal cell growth conditions GFP- eIF4A-III was mainly nucleoplasmic, but in hypoxia stress conditions it moved to the nucleolus and splicing speckles. This transition occurred within 15-20 min in Arabidopsis culture cells and seedling root cells, but took more than 2 h in tobacco BY-2 culture cells. Inhibition of respiration, transcription or phosphorylation in cells and ethanol treatment had similar effects to hypoxia. The most likely consequence is that a certain mRNA population will remain bound to the eIF4A-III and other mRNA processing proteins, rather than being transported from the nucleus to the cytoplasm, and thus its translation will be suspended.