Plant interstitial telomere motifs participate in the control of gene expression in root meristems

The promoters of Arabidopsis eEF1A genes contain a telomere motif, the telo -box, associated with an activating sequence, the tef-box. Database searche s indicated the presence of telo-boxes in the 5' region of numerous genes e ncoding components of the translational apparatus. By using several promote r constructs we demonstrate that the telo-box is required for the expressio n of a beta-glucoronidase gene in root primordia of transgenic Arabidopsis. This effect was observed when a telo-box was inserted upstream or downstre am from the transcription initiation site, and occurred in synergy with the tef-box. These results clearly indicate that interstitial telomere motifs in plants are involved in control of gene expression. South-western screeni ng of a lambda ZAP library with a double-stranded Arabidopsis telomere moti f resulted in characterization of a protein related to the conserved animal protein Pur alpha. The possibility of a regulation process similar to that achieved by the Rap1p in Saccharomyces cerevisiae is discussed.