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Transcription factor Zbtb1 interacts with bridging factor Lmo2 and maintains the T-lineage differentiation capacity of lymphoid progenitor cells

ABSTRACT: Hematopoietic stem and progenitor cells are able to differentiate into all blood cell types. Regulatory mechanisms underlying pluripotency in progenitors, such as the ability of lymphoid progenitor cells to differentiate into T-lineage, are not fully understood. We have previously reported that Lmo2, a bridging factor in large transcriptional complexes, is essential to retain the ability of lymphoid progenitors to differentiate into T-lineage. However, biochemical characterization of Lmo2 protein complexes in physiological hematopoietic progenitors has remained obscure. In this study, we identified around 600 of Lmo2 interacting molecules in a lymphoid progenitor cell line by two-step affinity purification with LC-MS/MS analysis. Among them, we found that Zbtb1 and Cbfa2t3 are functionally important binding partners of Lmo2. CRISPR/Cas9-mediated acute disruption of Zbtb1 or Cbfa2t3 in a lymphoid progenitor line or BM-derived primary hematopoietic progenitors caused significant defects in the initiation of T cell development when Notch signal is activated. Transcriptome analysis of Zbtb1- or Cbfa2t3-deficient lymphoid progenitors reveled that Tcf7, one the earliest Notch-target genes, is a common target of both factors. ChIP-seq analysis clearly showed that Lmo2, Zbtb1 and Cbfa2t3 co-bind to the Tcf7 upstream enhancer region, where is occupied by Notch intracellular domain/RBPJ transcriptional complex after Notch stimulation, in lymphoid progenitors. Moreover, transduction of Tcf7 restored the defect in the T-lineage potential of Zbtb1-deficient lymphoid progenitor cells. Thus, in lymphoid progenitors, Lmo2/Zbtb1/Cbfa2t3 complex directly binds to the Tcf7 locus and maintains responsiveness to the Notch-mediated inductive signaling for the T-lineage program.

ORGANISM(S): Mus musculus

PROVIDER: GSE199696 | GEO | 2022/09/10

REPOSITORIES: GEO

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