Diagenode

Ikaros antagonizes DNA binding by STAT5 in pre-B cells.


Heizmann, Beate and Le Gras, Stéphanie and Simand, Célestine and Marchal,Patricia and Chan, Susan and Kastner, Philippe

The IKZF1 gene, which encodes the Ikaros transcription factor, is frequently deleted or mutated in patients with B-cell precursor acute lymphoblastic leukemias that express oncogenes, like BCR-ABL, which activate the JAK-STAT5 pathway. Ikaros functionally antagonizes the transcriptional programs downstream of IL-7/STAT5 during B cell development, as well as STAT5 activity in leukemic cells. However, the mechanisms by which Ikaros interferes with STAT5 function is unknown. We studied the genomic distribution of Ikaros and STAT5 on chromatin in a murine pre-B cell line, and found that both proteins colocalize on >60\% of STAT5 target regions. Strikingly, Ikaros activity leads to widespread loss of STAT5 binding at most of its genomic targets within two hours of Ikaros induction, suggesting a direct mechanism. Ikaros did not alter the level of total or phosphorylated STAT5 proteins, nor did it associate with STAT5. Using sequences from the Cish, Socs2 and Bcl6 genes that Ikaros and STAT5 target, we show that both proteins bind overlapping sequences at GGAA motifs. Our results demonstrate that Ikaros antagonizes STAT5 DNA binding, in part by competing for common target sequences. Our study has implications for understanding the functions of Ikaros and STAT5 in B cell development and transformation.

Tags
IPure kit

Share this article

Published
January, 2020

Source

Products used in this publication

  • default alt
    C03010015
    IPure kit v2

Events

  • AACR 2024
    San Diego, California, USA
    Apr 5-Apr 10, 2024
 See all events

News

 See all news


The European Regional Development Fund and Wallonia are investing in your future.

Extension of industrial buildings and new laboratories.


       Site map   |   Contact us   |   Conditions of sales   |   Conditions of purchase   |   Privacy policy   |   Diagenode Diagnostics