The RNA-dependent RNA polymerase essential for post-transcriptional gene silencing in Neurospora crassa interacts with replication protein A
Author(s)
Type
Journal Article
Abstract
Post-transcriptional gene silencing (PTGS) pathways play a role in genome defence and have been extensively studied, yet how repetitive elements in the genome are identified is still unclear. It has been suggested that they may produce aberrant transcripts (aRNA) that are converted by an RNA-dependent RNA polymerase (RdRP) into double-stranded RNA (dsRNA), the essential intermediate of PTGS. However, how RdRP enzymes recognize aberrant transcripts remains a key question. Here we show that in Neurospora crassa the RdRP QDE-1 interacts with Replication Protein A (RPA), part of the DNA replication machinery. We show that both QDE-1 and RPA are nuclear proteins and that QDE-1 is specifically recruited onto the repetitive transgenic loci. We speculate that this localization of QDE-1 could allow the in situ production of dsRNA using transgenic nascent transcripts as templates, as in other systems. Supporting a link between the two proteins, we found that the accumulation of short interfering RNAs (siRNAs), the hallmark of silencing, is dependent on an ongoing DNA synthesis. The interaction between QDE-1 and RPA is important since it should guide further studies aimed at understanding the specificity of the RdRP and it provides for the first time a potential link between a PTGS component and the DNA replication machinery.
Date Issued
2008-02-01
Date Acceptance
2007-11-13
Citation
Nucleic Acids Research, 2008, 36 (2), pp.532-538
ISSN
0305-1048
Publisher
Oxford University Press
Start Page
532
End Page
538
Journal / Book Title
Nucleic Acids Research
Volume
36
Issue
2
Copyright Statement
© 2007 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Subjects
Science & Technology
Life Sciences & Biomedicine
Biochemistry & Molecular Biology
DNA-METHYLATION
SACCHAROMYCES-CEREVISIAE
REPEAT INSTABILITY
IN-VIVO
INTERFERENCE
SEQUENCES
HETEROCHROMATIN
LOCALIZATION
EXPRESSION
MUTATIONS
DNA, Fungal
Fungal Proteins
Gene Expression Regulation, Fungal
Genes, Essential
Neurospora crassa
Nuclear Proteins
RNA Interference
RNA Replicase
RNA, Small Interfering
Repetitive Sequences, Nucleic Acid
Replication Protein A
Transgenes
Neurospora crassa
RNA Replicase
Fungal Proteins
Nuclear Proteins
RNA, Small Interfering
DNA, Fungal
Gene Expression Regulation, Fungal
RNA Interference
Repetitive Sequences, Nucleic Acid
Genes, Essential
Transgenes
Replication Protein A
05 Environmental Sciences
06 Biological Sciences
08 Information and Computing Sciences
Developmental Biology
Publication Status
Published
Date Publish Online
2007-11-29