Gene regulation is controlled by proteins called transcription factors, which determine the differentiated state of cells. Pluripotent stem cells such as embryonic stem cells have the potential to differentiate into any cell type, depending on external stimuli. In one of the most amazing feats of trial and error in modern biomedical science, Shinya Yamanaka of Kyoto University and his team discovered that introduction of DNA encoding the genes for four mammalian transcription factors (Oct4, Sox2, c-Myc, and Klf4) into a differentiated cell was necessary and sufficient to cause induction of a pluripotent state. Using gene transfer techniques, methods were developed to generate induced pluripotent stem (iPS) cells that can be stimulated to differentiate into specific cell types and used for a variety of biochemical studies.
Everyday BioChem 