Abstract
The control of RNA degradation is central to the regulation of gene expression since rate of turnover also contributes to the steady-state levels of RNA molecules. There are two known pathways of eukaryotic RNA turnover. In one pathway, the RNA molecules are degraded by a 5'-3' exonuclease, while the other involves degradation by a complex of 3'-5' exonucleases (exosome). We found that ETHYLENE-INSENSITIVE5 is in fact the exoribonuclease XRN4 that participates in RNA degradation in a 5'-3' direction (1). To determine the substrates of EIN5/XRN4, we turned to tiling microarray analysis of the entire Arabidopsis genome. In addition, we have established a genetic depletion system for two of the Arabidopsis exosome subunits via an estradiol-inducible RNA interference (iRNAi), which is being used for transcriptome-wide definition of the plant exosome substrates, using tiling microarrays.
1. Gabriela Olmedo, et al., (2006) Proc. Natl. Acad. Sci USA. 103: 13286-93.
