The thyroid transcription factor-1 gene is a candidate target for regulation by Hox proteins.

摘要: Vertebrate Hox homeobox genes are transcription factors which regulate antero-posterior axial identity in embryogenesis, presumably through activation and/or repression of downstream target genes. Some these targets were reported to code for molecules involved cell-cell interactions, whereas no relationship has yet been demonstrated between and other determining maintaining tissue specificity. The thyroid factor-1 (TTF-1) is a homeodomain-containing protein required expression thyroid-specific A 862 bp 5' genomic fragment the rat TTF-1 gene, conferring reporter was sufficient mediate transactivation by human HOXB3 gene co-transfection assay both NIH3T3 or HeLa cells. expressed early mammalian embryogenesis anterior neuroectoderm, branchial arches their derivatives, including area primordia gland. Transcription promoter induced only HOXB3, while its paralogous HOXD3 more posteriorly (HOXA4, HOXD4, HOXC5, HOXC6, HOXC8 Hoxd-8) have effect. Transactivation mediated two binding sites containing an ATTA core located at -100 +30 from start site. DNase I footprinting experiments show that bind synthesized Escherichia coli eukaryotic cells, as well nuclear factor(s) present extracts obtained mouse embryonic tissues express group 3 TTF-1. DNA-protein complexes formed indistinguishable those generated HOXB3.(ABSTRACT TRUNCATED AT 250 WORDS)