A double-stranded-RNA response program important for RNA interference efficiency.
When recognized by the RNA interference (RNAi) pathway, double-stranded RNA (dsRNA) produced in eukaryotic cells results in posttranscriptional gene silencing. In addition, dsRNA can trigger the interferon response as part of the immune response in vertebrates. In this study, we show that dsRNA, but not short interfering RNA (siRNA), induces the expression of qde-2 (an Argonaute gene) and dcl-2 (a Dicer gene), two central components of the RNAi pathway in the filamentous fungus Neurospora crassa. The induction of QDE-2 by dsRNA is required for normal gene silencing, indicating that this is a regulatory mechanism that allows the optimal function of the RNAi pathway. In addition, we demonstrate that Dicer proteins (DCLs) regulate QDE-2 posttranscriptionally, suggesting a role for DCLs or siRNA in QDE-2 accumulation. Finally, a genome-wide search revealed that additional RNAi components and homologs of antiviral and interferon-stimulated genes are also dsRNA-activated genes in Neurospora. Together, our results suggest that the activation of the RNAi components is part of a broad ancient host defense response against viral and transposon infections.
Choudhary
Swati
S
Department of Physiology, Room ND13.214A, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9040, USA.
Lee
Heng-Chi
HC
Maiti
Mekhala
M
He
Qun
Q
Cheng
Ping
P
Liu
Qinghua
Q
Liu
Yi
Y
D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D020868:Gene Silencing; D016681:Genome, Fungal; D008969:Molecular Sequence Data; D009492:Neurospora crassa / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism
D005656:Fungal Proteins; C406184:QDE-2 protein, Neurospora crassa; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering; D043244:Ribonuclease III