concordant regulation of translation and mrna abundance for hundreds of targets of a human microrna整合调节翻译和mrna丰富数百人微的目标.pdfVIP

Concordant Regulation of Translation and mRNA Abundance for Hundreds of Targets of a Human microRNA David G. Hendrickson1., Daniel J. Hogan2,3., Heather L. McCullough2,3,4., Jason W. Myers2,3., Daniel Herschlag2*, James E. Ferrell1,2*, Patrick O. Brown2,3* 1 Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, United States of America, 2 Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America, 3 Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, United States of America, 4 Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America Abstract MicroRNAs (miRNAs) regulate gene expression posttranscriptionally by interfering with a target mRNA’s translation, stability, or both. We sought to dissect the respective contributions of translational inhibition and mRNA decay to microRNA regulation. We identified direct targets of a specific miRNA, miR-124, by virtue of their association with Argonaute proteins, core components of miRNA effector complexes, in response to miR-124 transfection in human tissue culture cells. In parallel, we assessed mRNA levels and obtained translation profiles using a novel global approach to analyze polysomes separated on sucrose gradients. Analysis of translation profiles for ,8,000 genes in these proliferative human cells revealed that basic features of translation are similar to those previously observed in rapidly growing Saccharomyces cerevisiae. For ,600 mRNAs specifically recruited to Argonaute proteins by miR-124, we found reductions in both the mRNA abundance and inferred translation rate spanning a large dynamic range. The changes in mRNA levels of these miR-124 targets were larger than the changes in translati