Article

The transcription factors E2A and HEB act in concert to induce the expression of FOXO1 in the common lymphoid progenitor.

Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 10/2011; 108(42):17402-7. DOI: 10.1073/pnas.1111766108
Source: PubMed

ABSTRACT Recent studies have identified a number of transcriptional regulators, including E proteins, EBF1, FOXO1, and PAX5, that act together to orchestrate the B-cell fate. However, it still remains unclear as to how they are linked at the earliest stages of B-cell development. Here, we show that lymphocyte development in HEB-ablated mice exhibits a partial developmental arrest, whereas B-cell development in E2A(+/-)HEB(-/-) mice is completely blocked at the LY6D(-) common lymphoid progenitor stage. We show that the transcription signatures of E2A- and HEB-ablated common lymphoid progenitors significantly overlap. Notably, we found that Foxo1 expression was substantially reduced in the LY6D(-) HEB- and E2A-deficient cells. Finally, we show that E2A binds to enhancer elements across the FOXO1 locus to activate Foxo1 expression, linking E2A and FOXO1 directly in a common pathway. In summary, the data indicate that the earliest event in B-cell specification involves the induction of FOXO1 expression and requires the combined activities of E2A and HEB.

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