A SWI2/SNF2-type ATPase/helicase protein, mDomino, interacts with myeloid zinc finger protein 2A (MZF-2A) to regulate its transcriptional activity.

The myeloid zinc finger protein 2A (MZF-2A) is a Krüppel-type C2H2 zinc finger transcription factor expressed in myeloid cells and involved in the growth, differentiation and tumorigenesis of myeloid progenitors. Previously we identified a 180 amino acid domain in MZF-2A which is responsible for the transcriptional activation of MZF-2A. To understand the mechanism of the MZF-2A-dependent transcriptional activation, we screened for molecules that interact with the transactivation domain (TAD) of MZF-2A. By using the yeast Ras recruitment two-hybrid screening, we identified a novel SWI2/SNF2-related protein, termed mammalian Domino (mDomino), as an MZF-2A-binding partner. The mDomino protein, which shows a marked similarity to the Drosophila Domino protein, contains a SWI2/SNF2-type ATPase/helicase domain, a SANT domain, and a glutamine-rich (Q-rich) domain. The C-terminal Q-rich domain of mDomino physically associates with the TAD of MZF-2A in mammalian cells as well as in yeast. Expression of the mDomino Q-rich domain, together with MZF-2A in myeloid LGM-1 cells, enhanced the MZF-2A-mediated activation of a reporter gene. These results strongly suggest that an ATP-dependent chromatin-remodelling complex containing mDomino interacts with MZF-2A to regulate gene expression in myeloid cells.