Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany.
Biochem J. 2013 Mar 1;450(2):427-32. doi: 10.1042/BJ20121713.
Selenoproteins are proteins carrying the rare amino acid Sec (selenocysteine). Full expression of selenoproteins requires modification of tRNA([Ser]Sec), including N(6)-isopentenylation of base A(37). We show that Trit1 is a dimethylallyl:tRNA([Ser]Sec) transferase. Knockdown of Trit1 reduces expression of selenoproteins. Incubation of in vitro transcribed tRNA[Ser]Sec with recombinant Trit1 transfers [(14)C]dimethylallyl pyrophosphate to tRNA([Ser]Sec). 37A>G tRNA([Ser]Sec) is resistant to isopentenylation by Trit1.
硒蛋白是携带稀有氨基酸硒代半胱氨酸（Sec）的蛋白质。硒蛋白的完全表达需要 tRNA（[Ser]Sec）的修饰，包括碱基 A（37）的 N（6）-异戊烯基化。我们表明 Trit1 是二甲基烯丙基：tRNA（[Ser]Sec）转移酶。Trit1 的敲低会降低硒蛋白的表达。用重组 Trit1 孵育体外转录的 tRNA[Ser]Sec 将 [(14)C]二甲基烯丙基焦磷酸转移到 tRNA（[Ser]Sec）上。37A>G tRNA（[Ser]Sec）对 Trit1 的异戊烯基化有抗性。
