These studies illustrate the non-overlapping roles and different modes of action of the various ATP-dependent chromatin remodellers in a single cell type, and they show that these remodellers have genetically non-redundant and programmatic roles in pluripotency, perhaps as a result of their coordinated action with the master regulatory transcription factors. Given the crucial roles of chromatin remodellers in pluripotency, it is curious that they were not identified in the search for factors capable of generating induced pluripotent stem (iPS) cells. The reason for this might be the strict stoichiometry of the complexes, the requirement for which is shown by the observation that overexpression of just one subunit often results in a dominant-negative phenotype.
