Expression of the bZIP transcription factor TCF11 and its potential dimerization partners during development

TCF11 (also known as Nrf1 and LCR-F1) is a basic-region leucine-zipper (b-Z IP) transcription factor that is essential during embryonic development. We have carried out expression analysis at a number of developmental stages a nd find that while there is some localized elevated expression between 8 an d 9 days post coitum (dpc), the gene is widely expressed with a constant le vel of mRNA transcripts detectable in all tissues and at all stages examine d. However, this does not reflect the specific nature of a TCF11 mutant phe notype (EMBO J. 17 (1998) 1779) which shows an essential role in foetal liv er haematopoiesis. The specificity of TCF11 function may be controlled at a posttranscriptional level including availability of, and specific interact ion with, a range of potential heterodimerization partners. We therefore ca rried out expression analysis of four candidate partner molecules; the thre e small Maf genes and another bZIP transcription factor found to bind to TC F11 in a two-hybrid screen, ATF4. We show different patterns of expression for the three Maf genes during development with MafG being widely expressed , MafK expressed only later in development and in specific tissues, and no detection of MafF. ATF4 shows evidence of complex regulation during develop ment and shows elevated expression in many of the same sites as TCF11. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.