Linked Life Data

8761945

Source:http://linkedlifedata.com/resource/pubmed/id/8761945

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-4-29
pubmed:abstractText
In eukaryotes, the synthesis of selenoproteins depends on an exogenous supply of selenium, required for synthesis of the novel amino acid, selenocysteine, and on the presence of a "selenium translation element" in the 3' untranslated region of mRNA. The selenium translation element is required to re-interpret the stop codon, UGA, as coding for selenocysteine incorporation and chain elongation. Messenger RNA lacking the selenium translation element and/or an inadequate selenium supply lead to chain termination at the UGA codon. We exploited these properties to provide direct translational control of protein(s) encoded by transfected cDNAs. Selenium-dependent translation of mRNA transcribed from target cDNA was conferred by mutation of an in-frame UGU, coding for cysteine, to UGA, coding for either selenocysteine or termination, then fusing the mutated coding region to a 3' untranslated region containing the selenium translation element of the human cellular glutathione peroxidase gene. In this study, the biological consequences of placing this novel amino acid in the polypeptide chain was examined with two proteins of known function: the rat growth hormone receptor and human thyroid hormone receptor beta 1. UGA (opal) mutant-STE fusion constructs of the cDNAs encoding these two polypeptides showed selenium-dependent expression and their selenoprotein products maintained normal ligand binding and signal transduction. Thus, integration of selenocysteine had little or no consequence on the functional activity of the opal mutants; however, opal mutants were expressed at lower levels than their wild-type counterparts in transient expression assays. The ability to integrate this novel amino acid at predetermined positions in a polypeptide chain provides selenium-dependent translational control to the expression of a wide variety of target genes, allows facile 75Se radioisotopic labeling of the heterologous proteins, and permits site-specific heavy atom substitution.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0730-2312
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
410-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Selenium-regulated translation control of heterologous gene expression: normal function of selenocysteine-substituted gene products.
pubmed:affiliation
Department of Physiology, University of Massachusetts Medical School, Worcester 01655, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't