Interplay between FLI-1 and the LDB1 complex in murine erythroleukemia cells and during megakaryopoiesis.

Transcription factors are key players in a broad range of cellular processes such as cell-fate decision. Understanding how they act to control these processes is of critical importance for therapy purposes. FLI-1 controls several hematopoietic lineage differentiation including megakaryopoiesis and erythropoiesis. Its aberrant expression is often observed in cancer and is associated with poor prognosis. We showed that FLI-1 interacts with the LDB1 complex, which also plays critical roles in erythropoiesis and megakaryopoiesis. In this study, we aimed to unravel how FLI-1 and the LDB1 complex act together in murine erythroleukemia cells and in megakaryocyte. Combining omics techniques, we show that FLI-1 enables the recruitment of the LDB1 complex to regulatory sequences of megakaryocytic genes and to enhancers. We show as well for the first time that FLI-1 is able to modulate the 3D chromatin organization by promoting chromatin looping between enhancers and promoters most likely through the LDB1 complex.