Linked Life Data

9123832

Source:http://linkedlifedata.com/resource/pubmed/id/9123832

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-4-21
pubmed:abstractText
The tobacco etch potyvirus (TEV) helper component-proteinase (HC-Pro, 460 amino acid residues) is a multifunctional protein involved in aphid-mediated transmission, genome amplification, polyprotein processing, and long-distance movement. To investigate the interrelationships between three of these functions, 25 alanine-scanning mutations affecting clusters of charged residues were introduced into the HC-Pro coding sequence. The resulting mutants were analyzed with respect to HC-Pro proteolytic activity in vitro, genome amplification in protoplasts, and long-distance movement in tobacco plants. Three classes of mutants were identified. Class I mutants (total of 17) were capable of genome amplification, long-distance movement, and HC-Pro proteolysis with efficiencies similar to parental virus. The class III mutant (total of 1) encoded a proteolytically debilitated HC-Pro and was replication-defective. Class II mutants (total of 7) encoded proteolytically active HC-Pro, but each exhibited a suppressed amplification phenotype that was characterized by a progressive shutoff during the course of infection in protoplasts. The class II mutants also exhibited defects in long-distance movement, accumulating to relative levels of 0 to 7.5% in noninoculated tissue. Wild-type HC-Pro supplied in trans was able to partially rescue the class II mutant amplification defects in protoplasts and long-distance movement defects in plants, although the extent of complementation of movement function varied for each mutant. Six of the seven class II mutations affected the central region of HC-Pro between residues 126 and 300, whereas only one affected the C-terminal proteolytic domain. These results indicate that the central region of HC-Pro is necessary for efficient genome amplification and long-distance movement, and that the one or more HC-Pro functions involved in these processes is at least partially trans-active. Additionally, the long-distance movement properties of a previously characterized HC-Pro-defective mutant (TEV-GUS/CCCE) were characterized further using grafted nontransgenic and HC-Pro-expressing transgenic plants. The results indicated that HC-Pro is required in both inoculated and noninoculated tissues to complement the TEV-GUS/CCCE movement defects.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0042-6822
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
228
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
251-62
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Genome amplification and long-distance movement functions associated with the central domain of tobacco etch potyvirus helper component-proteinase.
pubmed:affiliation
Department of Biology, Texas A&M University, College Station 77843, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.