Cloning of human hepatic nuclear factor 1 (HNF1) and chromosomal localization of its gene in man and mouse.

HNF1 is a transcription factor that is required for hepatocyte-specific expression of several genes, including albumin and fibrinogen. Rat HNF1-encoding cDNAs have recently been cloned, revealing that this factor is a distant member of the homeoprotein family. We have now isolated HNF1 clones from a human liver cDNA library by using a rat HNF1 cDNA-derived probe. The longest clone, HCL20, contains a sequence corresponding to the intact rat HNF1-coding region followed by a 3' nontranslated region and a poly(A) tail, hence representing an almost full-length HNF1 cDNA. Alignment of the human and rat sequences shows that HNF1 is highly conserved between the two species. The HNF1 gene was mapped by in situ hybridization and by RFLP analysis of interspecific mouse backcrosses to chromosomes 12q24.3 and 5F in human and mouse, respectively, establishing a new segmental homology between these two chromosomes.