title: Factors impacting the aminoglycoside-induced UGA stop codon readthrough in selenoprotein translation.
abstract: Aminoglycosides (AG) are oligosaccharide antibiotics that interfere with the small ribosomal subunit in aerobic, Gram-negative bacteria, causing pathogen-destructing error rates in their protein biosynthesis. Aminoglycosides also induce mRNA misinterpretation in eukaryotic cells, especially of the UGA (Opal)-stop codon, albeit to a lower extent. UGA recoding is essentially required for the incorporation of selenocysteine (Sec) into growing selenoproteins during translation. Selenocysteine incorporation requires the presence of a selenoprotein-specific stem-loop structure within the 3'-untranslated region of the mRNA, the so-called Sec-insertion sequence (SECIS) element. Interestingly, selenoprotein genes differ in their SECIS-element sequence and in their UGA base context. We hypothesized that the SECIS-element and the specific codon context synergize in controlling the effects of AG on stop codon readthrough. To this end, the SECIS-elements of glutathione peroxidase 1, glutathione peroxidase 4 and selenoprotein P transcripts were cloned into a reporter system and analyzed in combination with different UGA codon contexts. Our results indicate that a cytosine in position 4 (directly downstream of UGA) confers strongest effects on both the Se- and AG-dependent readthrough. Overall selenoprotein biosynthesis rate depends on the Se-status, AG concentration and the specific SECIS-element present in the transcript. These findings help to get a better understanding for the susceptibility of different transcripts towards AG-mediated interference with the biosynthesis of functional Se-containing selenoproteins, and highlight the importance of the Se-status for successful selenoprotein biosynthesis under antibiotic therapy.
authors.affiliation: Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D - 13353 Berlin, Germany.
authors.forename: Janine
authors.initials: J
authors.lastname: Martitz
authors.affiliation: Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D - 13353 Berlin, Germany.
authors.forename: Peter Josef
authors.initials: PJ
authors.lastname: Hofmann
authors.affiliation: Rheinische Friedrich-Wilhelms-Universität, Institut für Biochemie und Molekularbiologie, Bonn, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Johannes
authors.affiliation: Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D - 13353 Berlin, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Köhrle
authors.affiliation: Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D - 13353 Berlin, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Schomburg
authors.affiliation: Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D - 13353 Berlin, Germany. Electronic address: kostja.renko@charite.de.
authors.forename: Kostja
authors.initials: K
authors.lastname: Renko
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology*; D002478:Cells, Cultured; D018388:Codon, Terminator / Q000187:drug effects* / Q000235:genetics*; D057809:HEK293 Cells; D006801:Humans; D014176:Protein Biosynthesis / Q000187:drug effects*; D051140:Selenoproteins / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D000617:Aminoglycosides; D018388:Codon, Terminator; D051140:Selenoproteins
keywords: Aminoglycoside; Selenoprotein; Selenoproteom disruptor