ROG Background Information GATA-3, a T-cell specific zinc-finger transcription factor, is essential for the development, differentiation, and activation of T helper (Th) cells, which are capable of secreting high levels of cytokines (1–5). The GATA-3 interacting protein, ROG (repressor of GATA), represses the function of GATA-3 in part by preventing the binding of GATA-3 to its cognate DNA target sequence (1). Overexpression of ROG in Th cells specifically inhibits the production of cytokines Th1 and Th2, suggesting that ROG may regulate the differentiation of Th cells (1). Direct binding of ROG to DNA suggests that ROG is a potent negative regulator of Th cytokine genes as well as noncytokines genes (1). ROG is a lymphoid specific member of the POZ protein family that is expressed at very low levels in resting T-cells (1). Expression of ROG is substatially higher in both resting and activated B cells (1).
