Abstract
Sequences upstream of the 3'-terminal tRNA-like structure of brome mosaic virus RNAs have been predicted to fold into several stem-loop and pseudoknot structures. To elucidate the functional role of this upstream region, a series of deletions was made in cDNA clones of RNA-3, a genomic component not required for replication. These deletion mutants were transcribed in vitro and cotransfected with RNA-1 and RNA-2 into barley protoplasts. Deletion of single stem-loop structures gave progeny retaining near-wild-type accumulation levels. Constructions representing deletion of two or three stem-loops substantially lowered the accumulation of progeny RNA-3 relative to wild-type levels. RNA-3 mutants bearing deletions of longer sequences or of the entire region (delta PsKs RNA-3) replicated poorly, yielding no detectable RNA-3 or RNA-4 progeny. Levels of RNA-1 and RNA-2, in the presence of a mutant RNA-3, were found to increase relative to the accumulation observed in a complete wild-type transfection. The stability of delta PsKs RNA-3 in protoplasts was somewhat lower than that of wild-type RNA during the first 3 h postinoculation. Little difference in translatability in vitro of wild-type and RNA-3 constructs bearing deletions within the stem-loop region was observed, and Western immunoblot analysis of viral coat protein produced in transfected protoplasts showed that protein accumulation paralleled the amount of RNA-4 message produced from the various sequences evaluated. These results indicate that the RNA-3 pseudoknot region plays a minor role in translational control but contributes substantially to the overall replication of the brome mosaic virus genome.
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Claims 7
Claim · model-written summary
Single stem-loop deletions retained near-wild-type progeny accumulation.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaree1 - Treatment
- Deletion of single stem-loop structurese0
- Interactor
- brome mosaic virus
Brome mosaic virust0pathogen - Outcome
- progeny retaining near-wild-type accumulation levelse0
- Direction
- near-wild-typee0
- Comparator
- wild-typee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Deletion of single stem-loop structures gave progeny retaining near-wild-type accumulation levels”
t0“brome mosaic virus RNA-3”
e1“barley protoplasts”
Claim · model-written summary
Deletion of two or three stem-loops lowered progeny RNA-3 accumulation relative to wild type.
- Taxon
- barleyHordeum vulgaree1
- Treatment
- deletion of two or three stem-loopse0
- Interactor
- brome mosaic virusBrome mosaic virust0pathogen
- Outcome
- accumulation of progeny RNA-3e0
- Direction
- lowerede0
- Comparator
- wild-typee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“deletion of two or three stem-loops substantially lowered the accumulation of progeny RNA-3 relative to wild-type levels”
t0“brome mosaic virus RNA-3”
e1“barley protoplasts”
Claim · model-written summary
Longer deletions or deletion of the entire pseudoknot region yielded no detectable RNA-3 or RNA-4 progeny.
- Taxon
- barleyHordeum vulgaree1
- Treatment
- deletions of longer sequences or of the entire region (delta PsKs RNA-3)e0
- Interactor
- brome mosaic virusBrome mosaic virust0pathogen
- Outcome
- no detectable RNA-3 or RNA-4 progenye0
- Direction
- replicated poorlye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“RNA-3 mutants bearing deletions of longer sequences or of the entire region (delta PsKs RNA-3) replicated poorly, yielding no detectable RNA-3 or RNA-4 progeny”
t0“brome mosaic virus RNA-3”
e1“barley protoplasts”
Claim · model-written summary
RNA-1 and RNA-2 accumulation increased with mutant RNA-3 relative to complete wild-type transfection.
- Taxon
- barleyHordeum vulgaree1
- Treatment
- a mutant RNA-3e0
- Interactor
- brome mosaic virusBrome mosaic virust0pathogen
- Outcome
- Levels of RNA-1 and RNA-2e0
- Direction
- increasee0
- Comparator
- a complete wild-type transfectione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Levels of RNA-1 and RNA-2, in the presence of a mutant RNA-3, were found to increase relative to the accumulation observed in a complete wild-type transfection”
t0“brome mosaic virus RNA-3”
e1“barley protoplasts”
Claim · model-written summary
Delta PsKs RNA-3 was somewhat less stable than wild-type RNA during the first 3 hours.
- Taxon
- barleyHordeum vulgaree1
- Interactor
- brome mosaic virusBrome mosaic virust0pathogen
- Outcome
- stability of delta PsKs RNA-3e0
- Direction
- lowere0
- Qualifier
- during the first 3 h postinoculatione0
- Comparator
- wild-type RNAe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The stability of delta PsKs RNA-3 in protoplasts was somewhat lower than that of wild-type RNA during the first 3 h postinoculation”
e1“barley protoplasts”
t0“brome mosaic virus RNA-3”
Claim · model-written summary
RNA-3 stem-loop deletions showed little difference in in-vitro translatability from wild type.
- Taxon
- barleyHordeum vulgaree1
- Treatment
- RNA-3 constructs bearing deletions within the stem-loop regione0
- Interactor
- brome mosaic virusBrome mosaic virust0pathogen
- Outcome
- translatability in vitroe0
- Direction
- Little differencee0
- Comparator
- wild-typee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Little difference in translatability in vitro of wild-type and RNA-3 constructs bearing deletions within the stem-loop region was observed”
e1“barley protoplasts”
t0“brome mosaic virus RNA-3”
Claim · model-written summary
Coat-protein accumulation paralleled the amount of RNA-4 message in transfected protoplasts.
- Taxon
- barleyHordeum vulgaree1
- Interactor
- brome mosaic virusBrome mosaic virust0pathogen
- Gene
- RNA-4e0
- Outcome
- protein accumulatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“protein accumulation paralleled the amount of RNA-4 message produced from the various sequences evaluated”
e1“barley protoplasts”
t0“brome mosaic virus RNA-3”
The same questions in other papers
loss of function · Brome mosaic virus · Hordeum vulgare (barley)Positive and negative results
1 paper in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- positive
1 paper more in this group
See all 5 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.