Transcriptional regulation in early B cell development.
Transcription factors and signalling molecules are important for both lineage commitment and lineage-specific regulation. The B cell specification factor Pax5 plays a dual role in B lineage commitment. Simultaneously, it potentiates and limits lineage choice by activating genes that are required for the B cell program while repressing lineage-inappropriate genes; more than 100 of the latter have now been identified. In this context, repression of the tyrosine kinase Flt3 has been shown to be essential for B lineage commitment. Regulation of antigen receptor recombination constitutes another level at which lineage specificity is determined, and the identification of two factors, E47 and FOXP1, which regulate the activity of the recombinase enzymes in B lineage cells, provides insight into the mechanisms that determine this. New information regarding the control of ordered recombination and allelic exclusion comes from studies of cis-acting elements within the Ig loci.
Fuxa
Martin
M
The Department of Immunology and Molecular Pathology, Division of Infection and Immunity, University College London, London W1T 4JF, United Kingdom.
Skok
Jane A
JA
D000483:Alleles; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D019070:Cell Lineage / Q000235:genetics*; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D015322:Gene Rearrangement, B-Lymphocyte; D038041:Lymphopoiesis / Q000235:genetics*; D051379:Mice; D051757:PAX5 Transcription Factor / Q000235:genetics / Q000502:physiology*; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology; D051820:TCF Transcription Factors / Q000235:genetics / Q000502:physiology; D058125:Transcription Factor 7-Like 1 Protein; D014158:Transcription, Genetic
D051858:Forkhead Transcription Factors; C432917:Foxp1 protein, mouse; D051757:PAX5 Transcription Factor; C497282:Pax5 protein, mouse; D012097:Repressor Proteins; D051820:TCF Transcription Factors; C544913:Tcf7l1 protein, mouse; D058125:Transcription Factor 7-Like 1 Protein