Interaction of adenovirus VA RNAI with the protein kinase DAI: Nonequivalence of binding and function

Mellits, Kenneth H.; Kostura, Matthew; Mathews, Michael B.

doi:10.1016/0092-8674(90)90194-j

Cited by 92 publications

(98 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, the pH dependence is reversed for bp RNA, which lacks the (A⅐C) ϩ mismatch pair (Fig. 1). primary binding site and its complex central domain as the major determinant of inhibitory activity (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). Although far less extensively examined, prior mutagenesis suggested that an intact terminal stem structure, particularly adjacent to the central domain, might also contribute to inhibition of PKR (21).…”

Section: Discussionmentioning

confidence: 99%

“…1). The apical stem and central domain are responsible for binding and inhibition of PKR, respectively, and the structural requirements for these roles have been thoroughly dissected (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). Remarkably, this functional division (22) is mirrored by a structural division between the apical stem and the central domain, which are essentially independent domains within the VA RNA I global architecture (25).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Systematic Deletion of the Adenovirus-associated RNAI Terminal Stem Reveals a Surprisingly Active RNA Inhibitor of Double-stranded RNA-activated Protein Kinase

Wahid

Coventry

Conn

2008

Journal of Biological Chemistry

View full text Add to dashboard Cite

Adenoviruses use the short noncoding RNA transcript virusassociated (VA) RNA I to counteract two critical elements of the host cell defense system, innate cellular immunity and RNA interference, mediated by the double-stranded RNA-activated protein kinase (PKR) and Dicer/RNA-induced silencing complex, respectively. We progressively shortened the VA RNA I terminal stem to examine its necessity for inhibition of PKR. Each deletion, up to 15 bp into the terminal stem, resulted in a cumulative decrease in PKR inhibitory activity. Remarkably, however, despite significant apparent destabilization of the RNA structure, the final RNA mutant that lacked the entire terminal stem (TS⌬21 RNA) efficiently bound PKR and exhibited wild-type inhibitory activity. TS⌬21 RNA stability was strongly influenced by solution pH, indicating the involvement of a protonated base within the VA RNA I central domain tertiary structure. Gel filtration chromatography and isothermal titration calorimetry analysis indicated that wild-type VA RNA I and TS⌬21 RNA form similar 1:1 complexes with PKR but that the latter lacks secondary binding site(s) that might be provided by the terminal stem. Although TS⌬21 RNA bound PKR with wild-type K d , and overall change in free energy (⌬G), the thermodynamics of binding (⌬H and ⌬S) were significantly altered. These results demonstrate that the VA RNA I terminal stem is entirely dispensable for inhibition of PKR. Potentially, VA RNA I is therefore a truly bi-functional RNA; Dicer processing of the VA RNA I terminal stem saturates the RNA interference system while generating a "mini-VA RNA I " molecule that remains fully active against PKR.The interferon-induced double-stranded RNA (dsRNA) 4 -activated protein kinase (PKR) is a key component of the innate immune response that forms the first line of intracellular defense against viral infection (1, 2). PKR regulates translation initiation by phosphorylating the eukaryotic initiation factor 2 (eIF2) ␣-subunit at serine 51. The large increase in affinity of the phosphorylated form for its guanosine exchange factor (eIF2B) results in competitive inhibition and the reduction in available eIF2⅐GTP⅐Met-tRNA i Met ternary complex leads to a sharp reduction in both cellular and viral protein expression (3-5). Viruses devote large portions of their genomes to evading such host defenses and have evolved many different strategies to counter the PKR-mediated response (6). For example, Epstein-Barr virus and adenovirus produce large quantities of short noncoding RNA transcripts, EBER (7, 8) and VA RNAs, respectively (9, 10), that bind directly to PKR but inhibit rather than activate the kinase activity.All adenoviruses encode at least one VA RNA sequence (VA RNA I ) of ϳ160 nucleotides that is transcribed by the host RNA polymerase III and accumulates to very high concentrations in the late stages of infection (11, 12). Although VA RNA I sequences from different virus serotypes vary considerably, all can be drawn in a similar extended structure consisting of three major ...

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Systematic Deletion of the Adenovirus-associated RNAI Terminal Stem Reveals a Surprisingly Active RNA Inhibitor of Double-stranded RNA-activated Protein Kinase

Wahid

Coventry

Conn

2008

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Double-stranded RNA is a viral replication intermediate that has long been recognized as a PAMP associated with viral infection, including infections with large DNA viruses. Indeed, several large DNA viruses have acquired strategies of immune avoidance that circumvent the host intracellular dsRNA response pathways (45)(46)(47). Although CpG DNA is generally referred to as a "bacterial" product, recent evidence confirms that CpG DNA is a viral PAMP.…”

Section: Discussionmentioning

confidence: 99%

Synergistic Activation of Innate Immunity by Double-Stranded RNA and CpG DNA Promotes Enhanced Antitumor Activity

Whitmore¹,

et al. 2004

View full text Add to dashboard Cite

“…1) (15,32,36). Mutagenic studies indicate that the apical stem-loop is required for binding to PKR and that the central domain is involved in the inhibition of PKR activation (35)(36)(37). The terminal stem is essential for binding to Exp 5, which mediates VA transport to the cytoplasm (16,17).…”

mentioning

confidence: 99%

Adenovirus Virus-Associated RNA Is Processed to Functional Interfering RNAs Involved in Virus Production

Aparicio

Razquin

Zaratiegui

et al. 2006

J Virol

131

159

View full text Add to dashboard Cite

Posttranscriptional gene silencing allows sequence-specific control of gene expression. Specificity is guaranteed by small antisense RNAs such as microRNAs (miRNAs) or small interfering RNAs (siRNAs). Functional miRNAs derive from longer double-stranded RNA (dsRNA) molecules that are cleaved to pre-miRNAs in the nucleus and are transported by exportin 5 (Exp 5) to the cytoplasm. Adenovirus-infected cells express virus-associated (VA) RNAs, which are dsRNA molecules similar in structure to pre-miRNAs. VA RNAs are also transported by Exp 5 to the cytoplasm, where they accumulate. Here we show that small RNAs derived from VA RNAs (svaRNAs), similar to miRNAs, can be found in adenovirus-infected cells. VA RNA processing to svaRNAs requires neither viral replication nor viral protein expression, as evidenced by the fact that svaRNA accumulation can be detected in cells transfected with VA sequences. svaRNAs are efficiently bound by Argonaute 2, the endonuclease of the RNA-induced silencing complex, and behave as functional siRNAs, in that they inhibit the expression of reporter genes with complementary sequences. Blocking svaRNA-mediated inhibition affects efficient adenovirus production, indicating that svaRNAs are required for virus viability. Thus, svaRNA-mediated silencing could represent a novel mechanism used by adenoviruses to control cellular or viral gene expression.

show abstract

Interaction of adenovirus VA RNAI with the protein kinase DAI: Nonequivalence of binding and function

Cited by 92 publications

References 41 publications

Systematic Deletion of the Adenovirus-associated RNAI Terminal Stem Reveals a Surprisingly Active RNA Inhibitor of Double-stranded RNA-activated Protein Kinase

Systematic Deletion of the Adenovirus-associated RNAI Terminal Stem Reveals a Surprisingly Active RNA Inhibitor of Double-stranded RNA-activated Protein Kinase

Synergistic Activation of Innate Immunity by Double-Stranded RNA and CpG DNA Promotes Enhanced Antitumor Activity

Adenovirus Virus-Associated RNA Is Processed to Functional Interfering RNAs Involved in Virus Production

Contact Info

Product

Resources

About