The mammalian thioredoxin reductases (TrxR) are selenoproteins containing a catalytically
active selenocysteine residue (Sec) and are important enzymes in cellular redox control.
The cotranslational incorporation of Sec, necessary for activity, is governed by a stem-loop
structure in the 3′-untranslated region of the mRNA and demands adequate selenium
availability. The complicated translation machinery required for Sec incorporation is a major
obstacle in isolating mammalian cell lines stably overexpressing selenoproteins. In this work …