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Data Supplement from Validation and Structural Characterization of the LEDGF/p75–MLL Interface as a New Target for the Treatment of MLL-Dependent Leukemia

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posted on 2023-03-30, 22:44 authored by Kateřina Čermáková, Petr Tesina, Jonas Demeulemeester, Sara El Ashkar, Hélène Méreau, Juerg Schwaller, Pavlína Řezáčová, Vaclav Veverka, Jan De Rijck

Description of additional methods and procedures used in the study. Also includes supplementary references.

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ARTICLE ABSTRACT

Mixed lineage leukemia (MLL) fusion–driven acute leukemias represent a genetically distinct subset of leukemias with poor prognosis. MLL forms a ternary complex with the lens epithelium–derived growth factor (LEDGF/p75) and MENIN. LEDGF/p75, a chromatin reader recognizing H3K36me3 marks, contributes to the association of the MLL multiprotein complex to chromatin. Formation of this complex is critical for the development of MLL leukemia. Available X-ray data represent only a partial structure of the LEDGF/p75–MLL–MENIN complex. Using nuclear magnetic resonance spectroscopy, we identified an additional LEDGF/p75–MLL interface, which overlaps with the binding site of known LEDGF/p75 interactors—HIV-1 integrase, PogZ, and JPO2. Binding of these proteins or MLL to LEDGF/p75 is mutually exclusive. The resolved structure, as well as mutational analysis, shows that the interaction is primarily sustained via two aromatic residues of MLL (F148 and F151). Colony-forming assays in MLL–AF9+ leukemic cells expressing MLL interaction-defective LEDGF/p75 mutants revealed that this interaction is essential for transformation. Finally, we show that the clonogenic growth of primary murine MLL-AF9–expressing leukemic blasts is selectively impaired upon overexpression of a LEDGF/p75-binding cyclic peptide CP65, originally developed to inhibit the LEDGF/p75–HIV-1 integrase interaction. The newly defined protein–protein interface therefore represents a new target for the development of therapeutics against LEDGF/p75–dependent MLL fusion–driven leukemic disorders. Cancer Res; 74(18); 5139–51. ©2014 AACR.