Thu, 21 Aug 2008 01:19:14 BST CiteULike: heliopais's deadenylation http://www.citeulike.org/user/heliopais/tag/deadenylation CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/heliopais/article/520112 <i>Proc Natl Acad Sci U S A (22 February 2006)</i><br /><br />MicroRNAs (miRNAs) are ubiquitous regulators of eukaryotic gene expression. In addition to repressing translation, miRNAs can down-regulate the concentration of mRNAs that contain elements to which they are imperfectly complementary. Using miR-125b and let-7 as representative miRNAs, we show that in mammalian cells this reduction in message abundance is a consequence of accelerated deadenylation, which leads to rapid mRNA decay. The ability of miRNAs to expedite poly(A) removal does not result from decreased translation; nor does translational repression by miRNAs require a poly(A) tail, a 3' histone stem-loop being an effective substitute. These findings suggest that miRNAs use two distinct posttranscriptional mechanisms to down-regulate gene expression. MicroRNAs direct rapid deadenylation of mRNA. Ligang Wu Jihua Fan Joel G Belasco doi:10.1073/pnas.0510928103 Proc Natl Acad Sci U S A (22 February 2006) 2006-02-24T22:14:28-00:00 2006 Proc Natl Acad Sci U S A 0027-8424 deadenylation microrna