Faculty Opinions recommendation of RNA polymerase IV directs silencing of endogenous DNA.

2005 ◽  
Author(s):  
Daniel Gallie
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Iv

scholarly journals Identification of Pol IV and RDR2-dependent precursors of 24 nt siRNAs guiding de novo DNA methylation in Arabidopsis

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Todd Blevins ◽  
Ram Podicheti ◽  
Vibhor Mishra ◽  
Michelle Marasco ◽  
Jing Wang ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Cytosine Methylation ◽  
De Novo ◽  
Transferase Activity ◽  
Small Interfering Rnas ◽  
Pol Iv ◽  
Nuclear Rna ◽  
Rna Polymerase Iv ◽  
Nuclear Rna Polymerase

In Arabidopsis thaliana, abundant 24 nucleotide small interfering RNAs (24 nt siRNA) guide the cytosine methylation and silencing of transposons and a subset of genes. 24 nt siRNA biogenesis requires nuclear RNA polymerase IV (Pol IV), RNA-dependent RNA polymerase 2 (RDR2) and DICER-like 3 (DCL3). However, siRNA precursors are mostly undefined. We identified Pol IV and RDR2-dependent RNAs (P4R2 RNAs) that accumulate in dcl3 mutants and are diced into 24 nt RNAs by DCL3 in vitro. P4R2 RNAs are mostly 26-45 nt and initiate with a purine adjacent to a pyrimidine, characteristics shared by Pol IV transcripts generated in vitro. RDR2 terminal transferase activity, also demonstrated in vitro, may account for occasional non-templated nucleotides at P4R2 RNA 3’ termini. The 24 nt siRNAs primarily correspond to the 5’ or 3’ ends of P4R2 RNAs, suggesting a model whereby siRNAs are generated from either end of P4R2 duplexes by single dicing events.

RNA polymerase IV and transcriptional silencing

2005 ◽  
Vol 37 (7) ◽  
pp. 659-660 ◽  
Author(s):  
Hervé Vaucheret
Keyword(s):  
Rna Polymerase ◽  
Transcriptional Silencing ◽  
Rna Polymerase Iv

RNA Polymerase IV Functions in Paramutation in Zea mays

Science ◽  
2009 ◽  
Vol 323 (5918) ◽  
pp. 1201-1205 ◽  
Author(s):  
K. F. Erhard ◽  
J. L. Stonaker ◽  
S. E. Parkinson ◽  
J. P. Lim ◽  
C. J. Hale ◽  
...  
Keyword(s):  
Zea Mays ◽  
Rna Polymerase ◽  
Rna Polymerase Iv

scholarly journals Roles of RNA polymerase IV in gene silencing

2008 ◽  
Vol 13 (7) ◽  
pp. 390-397 ◽  
Author(s):  
Craig S. Pikaard ◽  
Jeremy R. Haag ◽  
Thomas Ream ◽  
Andrzej T. Wierzbicki
Keyword(s):  
Rna Polymerase ◽  
Gene Silencing ◽  
Rna Polymerase Iv

scholarly journals Reaction mechanisms of Pol IV, RDR2 and DCL3 drive RNA channeling in the siRNA-directed DNA methylation pathway

2019 ◽  
Author(s):  
Jasleen Singh ◽  
Vibhor Mishra ◽  
Feng Wang ◽  
Hsiao-Yun Huang ◽  
Craig S. Pikaard
Keyword(s):  
Dna Methylation ◽  
Rna Polymerase ◽  
Dna Transcription ◽  
Pol Iv ◽  
Methylation Pathway ◽  
Terminal Nucleotide ◽  
Passenger Strand ◽  
Rna Polymerase Iv ◽  
Rna Pathways ◽  
Template Dna

SummaryIn eukaryotes with multiple small RNA pathways the mechanisms that channel RNAs within specific pathways are unclear. Here, we reveal the reactions that account for channeling in the siRNA biogenesis phase of the Arabidopsis RNA-directed DNA methylation pathway. The process begins with template DNA transcription by NUCLEAR RNA POLYMERASE IV (Pol IV) whose atypical termination mechanism, induced by nontemplate DNA basepairing, channels transcripts to the associated RNA-dependent RNA polymerase, RDR2. RDR2 converts Pol IV transcripts into double-stranded RNAs then typically adds an extra untemplated 3’ terminal nucleotide to the second strands. The dicer endonuclease, DCL3 cuts resulting duplexes to generate 24 and 23nt siRNAs. The 23nt RNAs bear the untemplated terminal nucleotide of the RDR2 strand and are underrepresented among ARGONAUTE4-associated siRNAs. Collectively, our results provide mechanistic insights into Pol IV termination, Pol IV-RDR2 coupling and RNA channeling from template DNA transcription to siRNA guide strand/passenger strand discrimination.

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