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"Most viruses have double- or single-stranded RNA (ssRNA) genomes and produce long dsRNA helices during transcription and replication; the remainder of viruses

by samch 10y ago

"Most viruses have double- or single-stranded RNA (ssRNA) genomes and produce long dsRNA helices during transcription and replication; the remainder of viruses have DNA genomes and typically produce long dsRNA via symmetrical transcription." http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0022572 http://journals.plos.org/plosone/article?id=10.1371/journal....

openasocket 10y ago
Ah, I missed that. But which viruses generate dsRNA? Another trip to Google gave me the following paper from the Journal of Virology: "Double-stranded RNA is produced by positive-strand RNA viruses and DNA viruses but not in detectable amounts by negative-strand RNA viruses." (https://www.ncbi.nlm.nih.gov/pubmed/16641297 https://www.ncbi.nlm.nih.gov/pubmed/16641297) Assuming this paper is reputable (which I'm not really qualified to determine) that certainly seems to cover a broad category of viruses. If that paper is correct, negative strand RNA viruses (https://en.wikipedia.org/wiki/Negative-sense_single-stranded_RNA_virus https://en.wikipedia.org/wiki/Negative-sense_single-stranded...) would not be treatable with DRACO. And, according to wikipedia, that category includes Ebola, Rabies, Lassa virus and Hanta virus, which is a little disappointing. But here's the weird part. That wikipedia page also says that Influenza viruses are negative strand RNA viruses, so shouldn't produce dsRNA. But DRACO was tested against H1N1 influenza, and supposedly worked. We have a contradiction. So either the Journal of Virology paper is wrong, wikipedia is wrong is saying that Influenza is a negative strand RNA virus, or DRACO doesn't work against H1N1. Anyone care to offer some insight?
- virusduck 10y ago
  Influenza (and other (-)ssRNA viruses) are transcribed and replicated by an RNA-dependent RNA polymerase, that is, the protein makes +RNA out of a -RNA template. This replication is happening in the cytoplasm, and for at least a limited amount of time, there is dsRNA present, although I am not sure of the on/off time for this. The paper you cite uses an antibody to detect dsRNA, which may not be an adequate marker for dsRNA ( the RNA nay be in an incompatible confirmation for the Ab, proximety to proteins may cause the RNA to be fixed to viral or other proteins during fixation procedure, etc).
  - ihnorton 10y ago
    Son (2015) shows detection of dsRNA from (-)ssRNA viruses by immunofluorescence: http://jvi.asm.org/content/89/18/9383.full http://jvi.asm.org/content/89/18/9383.full They include this comment on the Weber (2006) paper cited above: > their lack of success might relate to the production of smaller amounts of dsRNA in negative-strand RNA virus infections, the use of the less sensitive J2 MAb, the choice of less than optimum times for p.i. sampling, or, possibly, technical issues.

by samch 10y ago

openasocket 10y ago

Ah, I missed that. But which viruses generate dsRNA? Another trip to Google gave me the following paper from the Journal of Virology: "Double-stranded RNA is produced by positive-strand RNA viruses and DNA viruses but not in detectable amounts by negative-strand RNA viruses." (https://www.ncbi.nlm.nih.gov/pubmed/16641297 https://www.ncbi.nlm.nih.gov/pubmed/16641297) Assuming this paper is reputable (which I'm not really qualified to determine) that certainly seems to cover a broad category of viruses. If that paper is correct, negative strand RNA viruses (https://en.wikipedia.org/wiki/Negative-sense_single-stranded_RNA_virus https://en.wikipedia.org/wiki/Negative-sense_single-stranded...) would not be treatable with DRACO. And, according to wikipedia, that category includes Ebola, Rabies, Lassa virus and Hanta virus, which is a little disappointing. But here's the weird part. That wikipedia page also says that Influenza viruses are negative strand RNA viruses, so shouldn't produce dsRNA. But DRACO was tested against H1N1 influenza, and supposedly worked. We have a contradiction. So either the Journal of Virology paper is wrong, wikipedia is wrong is saying that Influenza is a negative strand RNA virus, or DRACO doesn't work against H1N1. Anyone care to offer some insight?

virusduck 10y ago
Influenza (and other (-)ssRNA viruses) are transcribed and replicated by an RNA-dependent RNA polymerase, that is, the protein makes +RNA out of a -RNA template. This replication is happening in the cytoplasm, and for at least a limited amount of time, there is dsRNA present, although I am not sure of the on/off time for this. The paper you cite uses an antibody to detect dsRNA, which may not be an adequate marker for dsRNA ( the RNA nay be in an incompatible confirmation for the Ab, proximety to proteins may cause the RNA to be fixed to viral or other proteins during fixation procedure, etc).
- ihnorton 10y ago
  Son (2015) shows detection of dsRNA from (-)ssRNA viruses by immunofluorescence: http://jvi.asm.org/content/89/18/9383.full http://jvi.asm.org/content/89/18/9383.full They include this comment on the Weber (2006) paper cited above: > their lack of success might relate to the production of smaller amounts of dsRNA in negative-strand RNA virus infections, the use of the less sensitive J2 MAb, the choice of less than optimum times for p.i. sampling, or, possibly, technical issues.