BCL11A is a SUMOylated protein and recruits SUMO-conjugation enzymes in its nuclear body.

Abstract

BCL11A/EVI9 is a zinc-finger protein predominantly expressed in brain and hematopoietic cells. Previous studies show that BCL11A is involved in acute myelomonocytic leukemia and chronic lymphoid leukemia in mouse and human, respectively. Moreover, BCL11A is localized in the characteristic nuclear body in which BCL6 is co-localized. However, the significance of BCL11A in leukemogenesis and nuclear function remains unknown. In this study we show that BCL11A interacts with UBC9, a small ubiquitin-like modifier (SUMO) E2 conjugating enzyme, and recruits SUMO1 into the nuclear body. A lysine residue at amino acid 634 of BCL11A is SUMOylated but not required for the SUMO1 recruitment. The N-terminal region of BCL11A is responsible for SUMO1 recruitment as well as its nuclear body formation. We also show that SENP2, a SUMO specific peptidase, is co-localized in the nuclear body. These results suggest that BCL11A could be involved in the SUMO conjugation system, and that BCL11A might play an important role in protein modification.