The conversion of phosphoserine residues to selenocysteine residues on an opal suppressor tRNA and casein

Mizutani, Takaharu; Hitaka, Teruaki

doi:10.1016/0014-5793(88)80425-3

Cited by 25 publications

(10 citation statements)

References 23 publications

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“…The minor phosphoseryl-tRNA and another minor seryl-tRNA identified in bovine, rabbit, and chicken livers that decoded the stop codon UGA (12) were shown to be Sec tRNA [Ser]Sec (13). It was subsequently reported that phosphoseryl-tRNA [Ser]Sec was the intermediate in the biosynthesis of Sec in mammals (21,22) and in bacteria (23). However, after the identification of aminoacryltRNA [ (26).…”

Section: Discussionmentioning

confidence: 99%

Identification and characterization of phosphoseryl-tRNA ^[Ser]Sec kinase

Carlson

Kryukov

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

174

187

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In 1970, a kinase activity that phosphorylated a minor species of seryl-tRNA to form phosphoseryl-tRNA was found in rooster liver [Maenpaa, P. H. & Bernfield, M. R. (1970) Proc. Natl. Acad. Sci. USA 67, 688 -695], and a minor seryl-tRNA that decoded the nonsense UGA was detected in bovine liver. The phosphoseryl-tRNA and the minor UGA-decoding seryl-tRNA were subsequently identified as selenocysteine (Sec) tRNA [Ser]Sec , but the kinase activity remained elusive. Herein, by using a comparative genomics approach that searched completely sequenced archaeal genomes for a kinase-like protein with a pattern of occurrence similar to that of components of Sec insertion machinery, we detected a candidate gene for mammalian phosphoseryl-tRNA [ S elenocysteine (Sec) has its own code word, UGA, and its own tRNA, and therefore is viewed as the 21st amino acid in the genetic code (reviewed in refs. 1-4). Although UGA usually codes for the termination of protein synthesis, it also specifies Sec if specific requirements are met. The presence of a stemloop structure downstream of UGA, called a Sec insertion sequence (SECIS) element, is the critical component in selenoprotein mRNAs that dictates UGA to code for Sec (reviewed in ref. 5). In mammals, the SECIS element occurs in the 3Ј untranslated region of selenoprotein mRNAs. A specific elongation factor, EFsec, specifically recognizes selenocysteyltRNA [Ser]Sec (6, 7), and a SECIS element binding protein, SBP2, binds specifically to the SECIS element (8), directing the insertion of Sec into protein in response to UGA.It has been known for several years that the biosynthesis of Sec occurs on its tRNA in both bacteria (9) and mammals (10) after the tRNA is initially aminoacylated with serine by seryl-tRNA synthetase. In Escherichia coli, the pathway for the biosynthesis of Sec has been completely established (reviewed in ref. 1). After the aminoacylation of bacterial tRNA [Ser]Sec with serine, the hydroxyl group is removed from the seryl moiety to yield an aminoacrylyl intermediate, and this step is catalyzed by a pyridoxal phosphate-dependent Sec synthase. The aminoacrylyl intermediate serves as the acceptor for the activated selenium donor, monoselenophosphate, which is synthesized from selenite and ATP in the presence of selenophosphate synthetase (reviewed in ref. 1). Once selenium is donated to the intermediate, the biosynthesis of Sec on tRNA [Ser]Sec is complete.In eukaryotes, however, the biosynthesis of Sec has not been established, but several components have been identified over the years that play a role in this process. For example, in 1970, a minor seryl-tRNA was reported to form phosphoseryl-tRNA by a kinase activity from rooster liver (11), and a minor seryl-tRNA from bovine, rabbit, and chicken livers was reported to specifically decode the nonsense codon UGA (12). Although it was subsequently shown that both the minor seryl-tRNA that formed phosphoseryl-tRNA and the one that decoded UGA were the same tRNA (13), it was not known at the time these components were ...

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Section: Discussionmentioning

confidence: 99%

Identification and characterization of phosphoseryl-tRNA ^[Ser]Sec kinase

Carlson

Kryukov

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

174

187

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“…Following the landmark discovery of E. coli tRNA Sec in 1988 (7), it was speculated that Sep-tRNA might be an intermediate in Sec-tRNA Sec formation (8). In vitro synthesis of glutathione peroxidase in mouse extracts suggested that this was the case (33). However, the successful identification and characterization of E. coli SelA, the selenocysteine synthase that catalyzes SectRNA Sec formation directly from Ser-tRNA Sec (Fig.…”

Section: Sep-trna Is An Intermediate In Sec Biosynthesis In Eukaryotementioning

confidence: 99%

How an obscure archaeal gene inspired the discovery of selenocysteine biosynthesis in humans

Hohn

Palioura

et al. 2008

IUBMB Life

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“…Examination of the base sequence adjacent to the UGAs in the GPX and in formate dehydrogenase does not readily reveal a "consensus sequence" of bases that would differentiate a [Se]Cys-UGA from a termination UGA. To allow UGA to specify [Se]Cys rather than chain termination, Mizutani & Hitaka (52) proposed that a stem motif at the UGA was important. Mullenbach et al (55) have proposed that a lack of an adjacent stem motif may be critical.…”

Section: Cotranslational Se Incorporationmentioning

confidence: 99%