title: The pituitary-specific transcription factor GHF-1 is a homeobox-containing protein.
abstract: Growth hormone factor 1 (GHF-1) is a pituitary-specific transcription factor that plays a critical role in cell type-specific expression of the growth hormone (GH) gene. Here, we describe the isolation of bovine and rat GHF-1 cDNA clones. These cDNAs encode proteins whose molecular mass, 33K, is identical to purified GHF-1 and whose sequence agrees with a partial GHF-1 peptide sequence. The predicted GHF-1 sequence contains a region, near its C-terminus, that exhibits considerable similarity to a homeobox consensus sequence. DNAase I footprinting with bacterially expressed fusion protein containing a fragment of GHF-1 encompassing the homeobox indicates that this region of the protein functions as its DNA binding domain. Expression of GHF-1 is restricted to cells of the somatotropic lineage in the pituitary. This remarkable specificity of GHF-1 expression correlates with the selective transcription of its target, the GH gene. Other mammalian homeobox-containing proteins may function similarly as transcription factors controlling cell type-specific expression in other locations.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002846:Chromatography, Affinity; D004247:DNA / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D013006:Growth Hormone / Q000032:analysis / Q000235:genetics*; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D010902:Pituitary Gland / Q000032:analysis*; D051381:Rats; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D010455:Peptides; D014157:Transcription Factors; D013006:Growth Hormone; D004247:DNA