Selenoprotein Synthesis: A Unique Translational Mechanism Used by a Diverse Family of Proteins

The purpose of this review is to provide an overview of the unique mechanism by which mammalian selenoprotein synthesis occurs. Selenoprotein synthesis requires translational recoding of the UGA codon from a stop signal to a selenocysteine insertion signal (SECIS). Dedicated factors directly involved in this translation process include specific secondary structure in the mRNA (SECIS), a unique tRNA (Sec-tRNA^Sec), an RNA binding protein (SBP2), and a specialized elongation factor (EFsec). Regulation of this process is discussed along with physiologic and clinical issues regarding selenoprotein synthesis, including the side effects associated with statin drugs.