Publication Date:
2004-11-06
Description:
In RNA interference (RNAi), double-stranded RNA (dsRNA) triggers degradation of homologous messenger RNA. In many organisms, RNA-dependent RNA polymerase (RdRp) is required to initiate or amplify RNAi, but the substrate for dsRNA synthesis in vivo is not known. Here, we show that RdRp-dependent transgene silencing in Arabidopsis was caused by mutation of XRN4, which is a ribonuclease (RNase) implicated in mRNA turnover by means of decapping and 5'-3' exonucleolysis. When both XRN4 and the RdRp were mutated, the plants accumulated decapped transgene mRNA. We propose that mRNAs lacking a cap structure become exposed to RdRp to initiate or maintain RNAi.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gazzani, S -- Lawrenson, T -- Woodward, C -- Headon, D -- Sablowski, R -- BBS/E/J/00000594/Biotechnology and Biological Sciences Research Council/United Kingdom -- New York, N.Y. -- Science. 2004 Nov 5;306(5698):1046-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15528448" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Arabidopsis/*genetics
;
Arabidopsis Proteins/genetics
;
Exoribonucleases/genetics
;
Gene Silencing
;
Homeodomain Proteins/genetics
;
Mutation
;
Plant Proteins/genetics
;
Plants, Genetically Modified
;
RNA Caps
;
*RNA Interference
;
RNA Replicase/metabolism
;
RNA, Messenger/*metabolism
;
RNA, Plant/*metabolism
;
Rats
;
Recombinant Fusion Proteins/genetics
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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