Widespread translational inhibition by plant miRNAs and siRNAs.
High complementarity between plant microRNAs (miRNAs) and their messenger RNA targets is thought to cause silencing, prevalently by endonucleolytic cleavage. We have isolated Arabidopsis mutants defective in miRNA action. Their analysis provides evidence that plant miRNA-guided silencing has a widespread translational inhibitory component that is genetically separable from endonucleolytic cleavage. We further show that the same is true of silencing mediated by small interfering RNA (siRNA) populations. Translational repression is effected in part by the ARGONAUTE proteins AGO1 and AGO10. It also requires the activity of the microtubule-severing enzyme katanin, implicating cytoskeleton dynamics in miRNA action, as recently suggested from animal studies. Also as in animals, the decapping component VARICOSE (VCS)/Ge-1 is required for translational repression by miRNAs, which suggests that the underlying mechanisms in the two kingdoms are related.
Brodersen
Peter
P
Institut de Biologie Moléculaire des Plantes du CNRS, Unité Propre de Recherche 2357, 12 rue du Général Zimmer, 67084 Strasbourg Cedex, France.
Sakvarelidze-Achard
Lali
L
Bruun-Rasmussen
Marianne
M
Dunoyer
Patrice
P
Yamamoto
Yoshiharu Y
YY
Sieburth
Leslie
L
Voinnet
Olivier
O
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology; D060565:Argonaute Proteins; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins / Q000235:genetics; D000074201:Katanin; D035683:MicroRNAs / Q000502:physiology*; D009154:Mutation; D014176:Protein Biosynthesis; D012315:RNA Caps; D034622:RNA Interference; D018749:RNA, Plant / Q000502:physiology*; D034741:RNA, Small Interfering / Q000502:physiology*
D000251:Adenosine Triphosphatases; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D049452:Green Fluorescent Proteins; D000074201:Katanin; D035683:MicroRNAs; D012315:RNA Caps; D018749:RNA, Plant; D034741:RNA, Small Interfering; C117457:AGO1 protein, Arabidopsis; C529694:AT5G43810 protein, Arabidopsis; C483689:VARICOSE protein, Arabidopsis; C436244:KTN1 protein, Arabidopsis