EBF1

EBF1, or Early B-cell Factor 1, is a transcription factor in the Collier/Olf-1/EBF (COE) family. It was originally identified for its critical role in B cell development and is also known as Olf-1/EBF1. EBF1 is a master regulator of B lymphopoiesis, necessary for the commitment of common lymphoid progenitors to the B-cell lineage and for progression from pro-B to pre-B and mature B cells. It activates a B-cell gene program and works with other transcription factors such as E2A (TCF3) and RUNX1 to establish and maintain B-cell identity. EBF1 can autoregulate its own promoter, reinforcing sustained expression in developing B cells and contributing to a Pax5-centered regulatory loop that stabilizes the B-cell fate.

EBF1 expression is not limited to the B lineage. It is also involved in the development of other tissues, most notably olfactory sensory neurons, where it promotes neuronal differentiation, and in adipocytes, where it participates in adipogenesis. This broad expression reflects its role as a key differentiation factor in multiple lineages, with tissue-specific partners guiding its regulatory actions.

Genetic studies in mice show that loss of Ebf1 leads to a block in B cell development, with a marked reduction or absence of mature B cells. In humans, alterations or haploinsufficiency of EBF1 have been linked to hematologic malignancies such as B-cell acute lymphoblastic leukemia, underscoring its importance in normal B-cell development and the potential consequences of disrupted EBF1 function. EBF1 encodes a protein that binds DNA via a distinctive EBF DNA-binding domain and typically acts as a dimer, coordinating transcriptional programs through interactions with other factors.