Transcription factors and the regulation of haemopoiesis: lessons from GATA and SCL proteins.

One of the central issues of developmental biology concerns the molecular mechanisms whereby a multipotent cell gives rise to distinct differentiated progeny. Differences between specialised cell types reflect variations in their patterns of gene expression. The regulation of transcription initiation is an important control point for gene expression and it is, therefore, not surprising that transcription factors play a pivotal role in mammalian development and differentiation. Haemopoiesis offers a uniquely tractable system for the study of lineage commitment and differentiation. The importance of transcription factors in the normal regulation of haemopoiesis is underlined by the frequency with which transcription factors are targeted by leukaemogenic mutations. Studies of the function and regulation of haemopoietic transcription factors, especially those expressed in lineage-restricted patterns, should greatly increase our understanding of the molecular control of haemopoiesis. In this review we have focused on insights provided by recent studies of the GATA and SCL proteins.