Thu, 21 Aug 2008 07:09:15 BST CiteULike: hplatero's library [542 articles] http://www.citeulike.org/user/hplatero/article/1953979 CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/hplatero/article/1953979 <i>EMBO J, Vol. 18, No. 11. (1 June 1999), pp. 3139-3152.</i><br /><br />A novel form of post-transcriptional control is described. The 5' untranslated region (5'UTR) of the Saccharomyces cerevisiae gene encoding the AP1-like transcription factor Yap2 contains two upstream open reading frames (uORF1 and uORF2). The YAP2-type of uORF functions as a cis-acting element that attenuates gene expression at the level of mRNA turnover via termination-dependent decay. Release of post-termination ribosomes from the YAP2 5'UTR causes accelerated decay which is largely independent of the termination modulator gene UPF1. Both of the YAP2 uORFs contribute to the destabilization effect. A G/C-rich stop codon context, which seems to promote ribosome release, allows an uORF to act as a transferable 5'UTR-destabilizing element. Moreover, termination-dependent destabilization is potentiated by stable secondary structure 3' of the uORF stop codon. The potentiation of uORF-mediated destabilization is eliminated if the secondary structure is located further downstream of the uORF, and is also influenced by a modulatory mechanism involving eIF2. Destabilization is therefore linked to the kinetics of acquisition of reinitiation-competence by post-termination ribosomes in the 5'UTR. Our data explain the destabilizing properties of YAP2-type uORFs and also support a more general model for the mode of action of other known uORFs, such as those in the GCN4 mRNA. Post-termination ribosome interactions with the 5'UTR modulate yeast mRNA stability. C Vilela CV Ramirez B Linz C Rodrigues-Pousada JE McCarthy EMBO J, Vol. 18, No. 11. (1 June 1999), pp. 3139-3152. 2007-11-21T19:59:01-00:00 1999 EMBO J 0261-4189 18 11 3139 3152 mrna stability utr