TY - JOUR
T1 - Short RNAs repress translation after initiation in mammalian cells
AU - Petersen, Christian P.
AU - Bordeleau, Marie Eve
AU - Pelletier, Jerry
AU - Sharp, Phillip A.
N1 - Funding Information:
Suppressor tRNA plasmid was a kind gift from Dr. U. RajBhandary. HCV IRES sequences were a gift from Dr. S. Lemon. Hippuristanol was a kind gift of Dr. Junichi Tanaka (University of Ryukyus, Okinawa). C.P.P. acknowledges Dr. D. Housman, Dr. F. Goldberg, Dr. U. RajBhandary, and Sharp lab members for helpful conversations. This work was supported by United States Public Health Service RO1-GM34277 from the National Institutes of Health, PO1-CA42063 and U19 AI056900 from the National Cancer Institute to P.A.S., and partially by Cancer Center Support (core) grant P30-CA14051 from the National Cancer Institute and an National Cancer Institute of Canada grant (#014313) to J.P. C.P.P was funded in part by a National Science Foundation graduate research fellowship. J.P. is a Canadian Institutes of Health Research Senior Scientist.
PY - 2006/2/17
Y1 - 2006/2/17
N2 - MicroRNAs (miRNAs) are predicted to regulate 30% of mammalian protein-encoding genes by interactions with their 3′ untranslated regions (UTRs). We use partially complementary siRNAs to investigate the mechanism by which miRNAs mediate translational repression in human cells. Repressed mRNAs are associated with polyribosomes that are engaged in translation elongation, as shown by puromycin sensitivity. The inhibition appears to be postinitiation because translation driven by the cap-independent processes of HCV IRES and CrPV IRES is repressed by short RNAs. Further, metabolic labeling suggests that silencing occurs before completion of the nascent polypeptide chain. In addition, silencing by short RNAs causes a decrease in translational readthrough at a stop codon, and ribosomes on repressed mRNAs dissociate more rapidly after a block of initiation of translation than those on control mRNAs. These results suggest that repression by short RNAs, and thus probably miRNAs, is primarily due to ribosome drop off during elongation of translation.
AB - MicroRNAs (miRNAs) are predicted to regulate 30% of mammalian protein-encoding genes by interactions with their 3′ untranslated regions (UTRs). We use partially complementary siRNAs to investigate the mechanism by which miRNAs mediate translational repression in human cells. Repressed mRNAs are associated with polyribosomes that are engaged in translation elongation, as shown by puromycin sensitivity. The inhibition appears to be postinitiation because translation driven by the cap-independent processes of HCV IRES and CrPV IRES is repressed by short RNAs. Further, metabolic labeling suggests that silencing occurs before completion of the nascent polypeptide chain. In addition, silencing by short RNAs causes a decrease in translational readthrough at a stop codon, and ribosomes on repressed mRNAs dissociate more rapidly after a block of initiation of translation than those on control mRNAs. These results suggest that repression by short RNAs, and thus probably miRNAs, is primarily due to ribosome drop off during elongation of translation.
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U2 - 10.1016/j.molcel.2006.01.031
DO - 10.1016/j.molcel.2006.01.031
M3 - Article
C2 - 16483934
AN - SCOPUS:32444436121
SN - 1097-2765
VL - 21
SP - 533
EP - 542
JO - Molecular cell
JF - Molecular cell
IS - 4
ER -