Linked Life Data

2136781

Source:http://linkedlifedata.com/resource/pubmed/id/2136781

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-2-5
pubmed:abstractText
Minus strand RNA synthesis by the positive strand alphaviruses, Sindbis and Semliki Forest viruses, normally occurs early in infection, is coupled to synthesis of viral nonstructural proteins and to formation of viral replication complexes, and terminates and does not occur late in infection. Previously, ts24 of the A complementation group of Sindbis virus RNA-negative mutants was found to possess, among its other temperature sensitive defects, a temperature sensitivity in the normal cessation of minus strand synthesis which enabled minus strands to be synthesized late in infection at 40 degrees in the absence of protein synthesis. Revertants of ts24 (ts24R1, ts24R2) retained the defect in the shutoff of minus strand synthesis, indicating the lesion was not conditionally lethal and could map outside the A cistron. The studies reported here used an infectious clone of Sindbis virus to identify the mutation responsible for this phenotype. Hybrid viruses were prepared from constructs containing restriction fragments of the cDNA of ts24R1 in place of the corresponding fragments in the infectious SIN HR clone and screened for their ability to synthesize minus strands at 40 degrees in the presence of cycloheximide. A unique base change of an A for a C residue at nt 6339, predicting a change from glutamine to lysine at amino acid 195 in nsP4, was found in genomes of ts24, ts24R1, and ts24R2. Other nucleotide changes present at the 5' and 3' termini did not affect minus strand synthesis. The substitution of the parental Sindbis virus sequence that encompassed nt 6339 in an infectious clone of the ts24R1 revertant eliminated the mutant phenotype. We conclude that the ability to continue minus strand synthesis at 40 degrees exhibited by ts24 and its revertants is caused by an alteration in nsP4, which is the alphavirus replicase or an essential component of the replicase. We hypothesize that this domain of nsP4 functions to fix the minus strand as the stable template of alphavirus replication complexes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0042-6822
pubmed:author
pubmed:issnType
Print
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
43-52
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Temperature sensitive shut-off of alphavirus minus strand RNA synthesis maps to a nonstructural protein, nsP4.
pubmed:affiliation
Department of Microbiology, Medical College of Ohio, Toledo 43699.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't