Figure 6.

Hypothetic model in which ZEB2 and LMO2 use a similar oncogenic mechanism of action in T-cell acute lymphoblastic leukemia. LMO proteins do not bind DNA themselves, but nucleate a core multiprotein complex by acting as a bridge between 2 bHLH protein dimers that each recognizes a single E-box. As ZEB2 binds a similar double E-box DNA motif in its target promoters, we speculate that both LMO2 and ZEB2 activate a similar downstream signaling cascade and may explain the observed phenotypic similarities in Zeb2 overexpressing mouse and CD2-LMO2 transgenic animals. bHLH = basic helix-loop-helix, CID = CtBP interaction domain, CZF = carboxyterminal zinc finger domain, E = E-protein, HD = homeobox, NZF = aminoterminal zinc finger domain.