Selenoprotein O (SELENOO)

Selenoprotein O (SELENOO) is the largest mammalian selenoprotein, localized to mitochondria, and contains selenocysteine (Sec), a rare amino acid encoded by a UGA stop codon using a specialized RNA structure (SECIS element)[3][4][5]. SELENOO catalyzes the covalent transfer of adenosine monophosphate (AMP) onto serine, threonine, or tyrosine residues of target proteins, a modification known as AMPylation, particularly on proteins involved in redox homeostasis[2][4]. This activity suggests SELENOO helps regulate mitochondrial redox function and the cellular response to oxidative stress, but its full physiological roles remain incompletely defined[1][2][3][4]. SELENOO is evolutionarily conserved from bacteria to humans and is grouped among the lesser-known “alphabet selenoproteins” implicated broadly in antioxidant and redox-related processes[1]. There is currently no clinical use for SELENOO as a biomarker or therapeutic target, and no drugs are known to directly interact with it.

Other names

Protein adenylyltransferase SelO, mitochondrialSELOSelenoprotein O, mitochondrialSelO