Structural basis of DUX4/IGH-driven transactivation

Leukemia. 2018 Jun;32(6):1466-1476. doi: 10.1038/s41375-018-0093-1. Epub 2018 Mar 15.

Abstract

Oncogenic fusions are major drivers in leukemogenesis and may serve as potent targets for treatment. DUX4/IGHs have been shown to trigger the abnormal expression of ERGalt through binding to DUX4-Responsive-Element (DRE), which leads to B-cell differentiation arrest and a full-fledged B-ALL. Here, we determined the crystal structures of Apo- and DNADRE-bound DUX4HD2 and revealed a clamp-like transactivation mechanism via the double homeobox domain. Biophysical characterization showed that mutations in the interacting interfaces significantly impaired the DNA binding affinity of DUX4 homeobox. These mutations, when introduced into DUX4/IGH, abrogated its transactivation activity in Reh cells. More importantly, the structure-based mutants significantly impaired the inhibitory effects of DUX4/IGH upon B-cell differentiation in mouse progenitor cells. All these results help to define a key DUX4/IGH-DRE recognition/step in B-ALL.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • B-Lymphocytes / cytology
  • Cell Differentiation
  • Crystallization
  • DNA / metabolism
  • Homeodomain Proteins / chemistry*
  • Humans
  • Immunoglobulin Heavy Chains / chemistry*
  • Mutation
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / genetics*
  • Protein Domains
  • Transcriptional Activation*

Substances

  • DUX4L1 protein, human
  • Homeodomain Proteins
  • Immunoglobulin Heavy Chains
  • DNA