Pairing SOX off with partners in the regulation of embryonic development

The SOX family of high-mobility group (HMG) domain proteins has recently be en recognized as a key player in the regulation of embryonic development an d in the determination of the cell fate. In the case of certain SOX protein s, they regulate the target genes by being paired off with specific partner factors. This partnering: might allow SOX proteins to act in a cell-specif ic manner, which is key to their role in cell differentiation. The focus of this article is the mechanism of action of SOX proteins, in particular, ho w SOX proteins specifically pair off with respective partner factors and, a s a consequence, select distinct sets of genes as their regulatory targets.