Trans-acting factor that binds to glucocorticoid modulatory elements (GME) present in the TAT (tyrosine aminotransferase) promoter and increases sensitivity to low concentrations of glucocorticoids. Binds also to the transferrin receptor promoter (By similarity). Homodimer, and heterodimer of GMEB1 and GMEB2. Interacts with the glucocorticoid receptor (NR3C1) and NCOA2/TIF2. May interact with HSP27 and CREB-binding protein (CBP). Interacts with TRIM63 (By similarity). May be also cytoplasmic.