SelA, play different roles in Sec synthesis on one tRNA.
Sec (selenocysteine) is biosynthesized on its tRNA and incorporated into selenium-containing proteins (selenoproteins) as the 21st amino acid residue. Selenoprotein synthesis is dependent on Sec tRNA and the expression of this class of proteins can be modulated by altering Sec tRNA expression. The gene encoding Sec tRNA (Trsp) is a single-copy gene and its targeted removal in liver demonstrated that selenoproteins are essential for proper function wherein their absence leads to necrosis and hepatocellular degeneration. In the present study, we found that the complete loss of selenoproteins in liver was compensated for by an enhanced expression of several phase II response genes and their corresponding gene products. The replacement of selenoprotein synthesis in mice carrying mutant Trsp transgenes, wherein housekeeping, but not stress-related selenoproteins are expressed, led to normal expression of phase II response genes. Thus the present study provides evidence for a functional link between housekeeping selenoproteins and phase II enzymes.
GO:0097056 selenocysteinyl-tRNA(Sec) biosynthetic process
selenocysteinyl-tRNA(Sec) biosynthetic process - …
This tRNA is aminoacylated with a serine in a reaction catalyzed by the enzime seryl-tRNA synthetase (SerS) to generate the base structure for the Sec biosynthesis.
selenocysteinyl-trna(sec) biosynthetic process Antibodies
• The three-dimensional structure of SelA, the enzyme required for selenocysteine (Sec) synthesis, is determined.
• Four subunits of the huge star-shaped protein, SelA, play different roles in Sec synthesis on one tRNA.
• The findings will contribute to the development of superenzymes by facilitating introduction of selenium (Se) into enzymes.