uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The 5′-end heterogeneity of adenovirus virus-associated RNAI contributes to the asymmetric guide strand incorporation into the RNA-induced silencing complex
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
2009 (English)In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 37, no 20, 6950-6959 p.Article in journal (Refereed) Published
Abstract [en]

Human Adenovirus type 5 encodes two short RNA polymerase III transcripts, the virus-associated (VA) RNAI and VA RNAII, which can adopt stable hairpin structures that resemble micro-RNA precursors. The terminal stems of the VA RNAs are processed into small RNAs (mivaRNAs) that are incorporated into RISC. It has been reported that VA RNAI has two transcription initiation sites, which produce two VA RNAI species; a major species, VA RNAI(G), which accounts for 75% of the VA RNAI pool, and a minor species, VA RNAI(A), which initiates transcription three nucleotides upstream compared to VA RNAI(G). We show that this 5′-heterogeneity results in a dramatic difference in RISC assembly. Thus, both VA RNAI(G) and VA RNAI(A) are processed by Dicer at the same position in the terminal stem generating the same 3′-strand mivaRNA. This mivaRNA is incorporated into RISC with 200-fold higher efficiency compared to the 5′-strand of mivaRNAI. Of the small number of 5′-strands used in RISC assembly only VA RNAI(A) generated active RISC complexes. We also show that the 3′-strand of mivaRNAI, although being the preferred substrate for RISC assembly, generates unstable RISC complexes with a low in vitro cleavage activity, only around 2% compared to RISC assembled on the VA RNAI(A) 5′-strand.

Place, publisher, year, edition, pages
2009. Vol. 37, no 20, 6950-6959 p.
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:uu:diva-97775DOI: 10.1093/nar/gkp764ISI: 000271819900027PubMedID: 19755500OAI: oai:DiVA.org:uu-97775DiVA: diva2:172841
Available from: 2008-11-18 Created: 2008-11-18 Last updated: 2011-06-29Bibliographically approved
In thesis
1. Adenoviral Control of RNAi/miRNA Pathways in Human Cells
Open this publication in new window or tab >>Adenoviral Control of RNAi/miRNA Pathways in Human Cells
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

RNA interference (RNAi) is a diverse, conserved regulatory mechanism in eukaryotic cells, which silences the target gene expression in a homology-dependent manner. Although it has been well documented that RNAi is an antiviral mechanism in plants and insects, it is still unclear whether RNAi naturally limits viral infections in vertebrates. Viruses are masters of adopting strategies to subvert cellular defense mechanisms. Not only can viruses use elaborate strategies to suppress the effects of defensive RNAi, but they can also redirect or interfere with cellular functions orchestrated by endogenous small RNAs.

In our work we have focused on studying the relationship of human adenovirus type 5 (Ad5) infection and the RNAi/miRNA pathways. We show that Ad5 infection inhibits RNAi by blocking the activity of Dicer and the RNA-induced silencing complex (RISC). For Dicer inhibition, the virus-associated RNAs, VA RNAI and VA RNAII bind Dicer through their terminal stems and are cleaved by Dicer into functional small RNAs that are incorporated into active RISC.

Furthermore, by cloning small RNAs, we found that approximately 80% of Ago2-containing RISC immunopurified from late infected cells was associated with VA RNA-derived small RNAs (mivaRNAs). Interestingly, the small RNAs derived from VA RNAII, the minor VA RNA species, appear to be the major mivaRNAs occupying RISC and associate with polyribosomes, which indicates their potential roles as miRNAs regulating translation of cellular mRNAs.

During our previous work, we observed that the strand bias of VA RNAI derived small RNA (mivaRI) incorporating into active RISC varied in the different viable Ad5 mutant viruses infected cells. It has been reported that Ad5 VA RNAI had two transcription initiation sites, which produced two clusters of VA RNAI with 3 nt difference at their 5’ end. Our data show that this heterogeneity resulted in a dramatic difference in mivaRI guide strand selection.

Collectively, our data contributes to understanding the interplay between virus and host. This study would be beneficial in designing optimal adenovirus vectors for therapeutic RNAi application.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2008. 66 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 397
Keyword
Adenovirus, RNAi, miRNA, VA RNA
National Category
Microbiology in the medical area
Identifiers
urn:nbn:se:uu:diva-9387 (URN)978-91-554-7339-6 (ISBN)
Public defence
2008-12-10, C8:301, Biomedical Center, Husargatan 3, Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2008-11-18 Created: 2008-11-18 Last updated: 2009-10-14Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Authority records BETA

Akusjärvi, Göran

Search in DiVA

By author/editor
Akusjärvi, Göran
By organisation
Department of Medical Biochemistry and Microbiology
In the same journal
Nucleic Acids Research
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 708 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf