Peer-Reviewed Journal Details
Mandatory Fields
Howard, MT,Aggarwal, G,Anderson, CB,Khatri, S,Flanigan, KM,Atkins, JF;
2005
April
The Embo Journal
Recoding elements located adjacent to a subset of eukaryal selenocysteine-specifying UGA codons
Validated
()
Optional Fields
readthrough redefinition selenocysteine selenoprotein termination MURINE LEUKEMIA-VIRUS ELONGATION-FACTOR SELB SELENOPROTEIN MESSENGER-RNAS GAG-TERMINATION CODON READ-THROUGH STOP CODON SELENOPHOSPHATE SYNTHETASE MAMMALIAN SELENOPROTEIN IMMEDIATELY DOWNSTREAM MUSCULAR-DYSTROPHY
24
1596
1607
Incorporation of the 21st amino acid, selenocysteine, into proteins is specified in all three domains of life by dynamic translational redefinition of UGA codons. In eukarya and archaea, selenocysteine insertion requires a cis-acting selenocysteine insertion sequence ( SECIS) usually located in the 3'UTR of selenoprotein mRNAs. Here we present comparative sequence analysis and experimental data supporting the presence of a second stop codon redefinition element located adjacent to a selenocysteine-encoding UGA codon in the eukaryal gene, SEPN1. This element is sufficient to stimulate high-level (6%) translational redefinition of the SEPN1 UGA codon in human cells. Readthrough levels further increased to 12% when tested in the presence of the SEPN1 3'UTR SECIS. Directed mutagenesis and phylogeny of the sequence context strongly supports the importance of a stem loop starting six nucleotides 3' of the UGA codon. Sequences capable of forming strong RNA structures were also identified 3' adjacent to, or near, selenocysteine-encoding UGA codons in the Sps2, SelH, SelO, and SelT selenoprotein genes.
DOI 10.1038/sj.emboj.7600642
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