Linked Life Data

9261187

Source:http://linkedlifedata.com/resource/pubmed/id/9261187

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
1997-9-15
pubmed:abstractText
tat, an essential gene of human immunodeficiency virus, when placed under the control of the RNA polymerase III promoter from the adenovirus VA RNA1 gene, is transcribed into an uncapped and nonpolyadenylated mRNA. This VA-Tat RNA is translated to produce functional Tat protein in transfected mammalian cells (Gunnery, S., and Mathews, M. B. (1995) Mol. Cell. Biol. 15, 3597-3607). The presence of an upstream open reading frame (ORF) in VA-Tat RNA is inhibitory to the translation of the Tat ORF, suggesting that the RNA is scanned during translation even though it is uncapped. Because the effect of the upstream ORF is relatively small (about 2-fold), we sought more definitive evidence of scanning by introducing secondary structures of varying stabilities into the 5'-untranslated region of VA-Tat RNA. The results of transfection experiments showed that highly stable secondary structure was inhibitory to Tat synthesis, whereas structures of lower stability were not inhibitory, confirming that uncapped mRNA is subject to scanning. Furthermore, translation of the downstream ORF was reduced but not eliminated by mutations that caused the upstream ORF to overlap the Tat ORF. Extending the overlap of the two ORFs further decreased the translation of the downstream ORF. This observation implies that ribosomes reinitiate after termination, possibly after migrating in a 3' to 5' direction through the overlap region of the mRNA. Similar results were obtained with a capped polymerase II transcript, indicating that the translation of polymerase II and polymerase III transcripts occurs through similar mechanisms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21642-6
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Translation of an uncapped mRNA involves scanning.
pubmed:affiliation
Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.