| Autor: |
M G Sandbaken, K E Hill, Byeong Jae Lee, Raymond F. Gesteland, Takeshi Ohama, A J Wahba, Vijaya Karoor, G. T. Mullenbach, J E Jung, John F. Atkins |
| Rok vydání: |
1994 |
| Předmět: |
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| Zdroj: |
Journal of Biological Chemistry. 269:29739-29745 |
| ISSN: |
0021-9258 |
| DOI: |
10.1016/s0021-9258(18)43943-9 |
| Popis: |
The UGA selenocysteine (Sec) codon in glutathione peroxidase mRNA and in selenoprotein P and the UGA stop codon in rabbit beta-globin mRNA were employed to study the utilization of Sec-tRNA[Ser]Sec and Ser-tRNA[Ser]Sec in protein synthesis. In vitro Ser-tRNA[Ser]Sec served as a suppressor of the UGA Sec codon as well as the UGA stop codon, while Sec-tRNA[Ser]Sec did not. However, in vivo Sec-tRNA[Ser]Sec did donate Sec to glutathione peroxidase in Xenopus oocytes microinjected with glutathione peroxidase mRNA and Sec-tRNA. A ribosome binding assay was devised to investigate the interaction of aminoacyl-tRNA, rabbit reticulocyte ribosomes, and eukaryotic elongation factor 1 (eEF-1) in response to the appropriate trinucleoside diphosphate template. Ser-tRNA[Ser]Sec bound weakly to ribosomes in the presence of eEF-1 and UGA as compared to Phe-tRNA, Ser-tRNAIGA, and Met-tRNAm which bound more efficiently in the presence of eEF-1 and the appropriate template. No increase in the binding of Sec-tRNA[Ser]Sec was observed under the same conditions as Ser-tRNA[Ser]Sec. The ribosome binding studies substantiated the finding that Ser-tRNA[Ser]Sec serves as a suppressor of UGA codons in protein synthesis, but Sec-tRNA[Ser]Sec does not. In addition, these studies provide strong evidence that a specific elongation factor is required in mammalian cells for insertion of Sec into protein from Sec-tRNA[Ser]Sec. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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