Doing nature one better: Expanding the genetic code in living mammalian cells

Researchers at the Salk Institute for Biological Studies have developed a novel strategy to expand the natural repertoire of 20 amino acids in mammalian cells, including neurons, and successfully inserted tailor-made amino acids into proteins in these cells. In a powerful demonstration of the method’s versatility, they then used unnatural amino acids to determine the operating mechanism of the “molecular gates” that regulate the movement of potassium ions in and out of nerve cells.