ABSTRACT
Selenoproteins contain the rare amino acid selenocysteine. Because of the fundamental role of codonreassignment in selenoprotein biosynthesis, it is believed that understanding selenoprotein biosynthesis leads to a better understanding of translation and many more molecular biological processes involved in selenoprotein expression. There are 25 genes encoding selenoproteins in humans and 24 in mice. Despite the small number of selenoproteins, they are important for many biological processes, and some selenoproteins are essential for life. Accordingly, mutations in selenoproteins, or in any of the genes required for selenoprotein biosynthesis, lead to pathology in humans carrying such mutations, as well as in mouse models designed to be deficient for these genes. Work on the individual roles of selenoproteins was initially spearheaded by transgenic mouse models, but with the advent of the availability of whole exome sequencing, more and more patients deficient in selenoprotein genes or biosynthesis factors are being discovered.
