PHF6 interacts with the LMO2 complex in T-cell acute lymphoblastic leukemia

The transcriptional mediator LIM domain only 2 (LMO2) forms a large multi-protein complex together with TAL1/LYL1, HEB/ E2A, LDB1 and GATA. This complex regulates transcription from the onset of hematopoietic development and during differentiation. Chromosomal re-arrangements involving LMO2 and TAL1 are causative for T-cell lymphoblastic leukemia (T-ALL). We have identified Plant Homeodomain (PHD)-like Finger 6 (PHF6) as a new LMO2-interacting factor. Somatic mutations in PHF6 have been found to occur in several types of leukemia. We show that PHF6 interacts with LMO2 as a part of the TAL1, GATA2, LDB1 complex in T-ALL and binds to the DNA. These findings show that PHF6 associates with the TAL1/LMO2/LDB1/ GATA2 complex and regulates genes that have a major role in blood development, such as SPI1 (PU.1).