Selenoprotein biosynthesis

Selenoprotein biosynthesis is not a single molecular target but rather a complex cellular process responsible for the incorporation of the amino acid selenocysteine into specific proteins known as selenoproteins. This process is unique because it recodes the UGA stop codon in mRNA to specify insertion of selenocysteine via a specialized mechanism involving several dedicated factors. Key components include: - The SECIS element, a stem-loop structure in the 3' untranslated region (UTR) of mRNAs encoding selenoproteins. - SECIS-binding protein 2 (SBP2), which binds SECIS and recruits other factors. - A specialized tRNA^Sec^ that is first charged with serine by conventional enzymes and then converted enzymatically to carry selenocysteine using selenium derived from dietary sources. - A unique elongation factor (eEFSec) that delivers Sec-tRNA^Sec^ to ribosomes at UGA codons within appropriate mRNAs. This machinery ensures precise and safe incorporation of selenium into essential antioxidant enzymes such as glutathione peroxidases, thioredoxin reductases, and iodothyronine deiodinases. Errors or deficiencies in this pathway can result in reduced activity or absence of these critical enzymes, leading to increased oxidative stress and disease susceptibility[1][3][5]. Because "Selenoprotein biosynthesis" refers to an entire biochemical pathway rather than an individual receptor/protein/enzyme/targetable entity, it should not be considered a canonical therapeutic target itself. Instead, its components—such as SBP2 or eEFSec—could be considered targets if specifically referenced.

Other names

Selenocysteine incorporationSec biosynthesisSelenoprotein synthesis pathway