HEPATOCYTE NUCLEAR FACTOR-6, A TRANSCRIPTION FACTOR THAT CONTAINS A NOVEL TYPE OF HOMEODOMAIN AND A SINGLE CUT DOMAIN

Tissue-specific transcription is regulated in part by cell type-restri cted proteins that bind to defined sequences in target genes, The DNA- binding domain of these proteins is often evolutionarily conserved, On this basis, Liver-enriched transcription factors were classified into five families. We describe here the mammalian prototype of a sixth fa mily, which we therefore call hepatocyte nuclear factor 6 (HNF-6). It activates the promoter of a gene involved in the control of glucose me tabolism, HNF-6 contains two different DNA-binding domains, One of the se corresponds to a novel type of homeodomain. The other is homologous to the Drosophila cut domain. A similar bipartite sequence is coded b y the genome of Caenorhabditis elegans.