Noncoding transcription by RNA Polymerase Pol IVb/Pol V mediates transcriptional silencing of overlapping and adjacent genes

By Andrzej Wierzbicki, J. Haag, Craig S. Pikaard. Cell, 2008

719 citations recorded by the source corpus.

Nuclear transcription is not restricted to genes, but occurs throughout the intergenic and noncoding space of eukaryotic genomes. The functional significance of this widespread noncoding transcription is mostly unknown. We show that Arabidopsis RNA Polymerase IVb/Pol V, a multi-subunit nuclear enzyme required for siRNA-mediated gene silencing of transposons and other repeats, transcribes intergenic and noncoding sequences, thereby facilitating heterochromatin formation and silencing of overlapping and adjacent genes. Pol IVb/Pol V transcription requires the chromatin remodeling protein, DRD1 but is independent of siRNA biogenesis. However, Pol IVb/Pol V transcription and siRNA production are both required to silence transposons, suggesting that Pol IVb/Pol V generates RNAs or chromatin structures that serve as scaffolds for siRNA-mediated heterochromatin forming complexes. Pol IVb/Pol V function provides a solution to a paradox of epigenetic control: the need for transcription in order to transcriptionally silence the same region.

Subfields: Molecular Biology, Plant Science

View Paper: https://www.semanticscholar.org/paper/cb8dce1bd4898fcba1a8a43796554b8859f84511

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Molecular Biology

1. Jian‐Kang Zhu
2. Steven E. Jacobsen
3. Julie A. Law
4. Xuemei Chen
5. David Tollervey
6. E. Sontheimer
7. J. Houseley
8. Richard W. Carthew

In Plant Science

1. Jian‐Kang Zhu
2. Julie A. Law
3. Steven E. Jacobsen
4. Xuemei Chen
5. E. Sontheimer
6. Richard W. Carthew
7. Ramanjulu Sunkar
8. David P. Bartel

Citations in the corpus

• Origins and Mechanisms of miRNAs and siRNAs (2009, background): “…of dedicated DNA-dependent RNA polymerases, RNA Pol IV and Pol V, in the synthesis of siRNA precursors (Herr et al., 2005; Onodera et al., 2005; Wierzbicki et al., 2008). siRNA-directed transcriptional silencing is a fascinating and fast-moving field that has recently been reviewed in depth…”
• Small RNAs and Their Roles in Plant Development (2009, background): “DRD1, a potential chromatin remodeling protein, and DMS3, a structural maintenance of chromosomes (SMC) hinge-domain protein, are required for the production of Pol V transcripts and for siRNA-mediated heterochromatin formation (Kanno et al. 2004, 2008; Wierzbicki et al. 2008, 2009).”
• The many pathways of RNA degradation. (2009, background): “In plants, two additional RNA polymerases have been characterized (see Wierzbicki et al., 2008).”
• Active DNA Demethylation Mediated by DNA Glycosylases (2009, positive): “The KTF1 protein binds AGO4 and nascent transcripts generated by Pol V (103), thus serving as a bridge between the effector complex and siRNA target loci (33).”
• Mechanisms and Functions of Long Non-Coding RNAs at Multiple Regulatory Levels (2019, background): “Simultaneously, the transcriptional mechanism of RdDM primarily depends on two plant-specific RNA polymerases: Pol IV and Pol V [2,39].”
• Establishing, maintaining and modifying DNA methylation patterns in plants and animals (2010, background): “A recent study further clarified the role of Pol V in RdDM by identifying low-abundance intergenic non-coding (IGN) transcripts from several loci that depend on Pol V for their accumulatio”