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Updated: Jun 24, 2026

Immunostaining for DNA Modifications: Computational Analysis of Confocal Images
Published on: September 7, 2017
RNA-directed DNA methylation requires an AGO4-interacting member of the SPT5 elongation factor family
Natacha Bies-Etheve1, Dominique Pontier, Sylvie Lahmy
1Laboratoire Génome et Développement des Plantes, Université de Perpignan, 52 Avenue Paul Alduy, Bâtiment C, Perpignan Cedex 66860, France.
Abstract:
Recent studies have identified a conserved WG/GW-containing motif, known as the Argonaute (AGO) hook, which is involved in the recruitment of AGOs to distinct components of the eukaryotic RNA silencing pathways. By using this motif as a model to detect new components in plant RNA silencing pathways, we identified SPT5-like, a plant-specific AGO4-interacting member of the nuclear SPT5 (Suppressor of Ty insertion 5) RNA polymerase (RNAP) elongation factor family that is characterized by the presence of a carboxy-terminal extension with more than 40 WG/GW motifs. Knockout SPT5-like mutants show a decrease in the accumulation of several 24-nt RNAs and hypomethylation at different loci revealing an implication in RNA-directed DNA methylation (RdDM). Here, we propose that SPT5-like emerged in plants as a facultative RNAP elongation factor. Its plant-specific origin and role in RdDM might reflect functional interactions with plant-specific RNA Pols required for RdDM.
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