Hepatocyte-specific promoter element HP1 of the Xenopus albumin gene interacts with transcriptional factors of mammalian hepatocytes.
By transfecting various Xenopus albumin-CAT fusion genes into the mouse hepatoma cell line BW1J a 13 base-pair hepatocyte-specific promoter element (HP1) could be identified. A similar sequence element is also present in the promoter of the albumin and alpha-fetoprotein genes of other vertebrates. Introduction of single point mutations into HP1 destroys its function. Binding studies with nuclear proteins identify a factor interacting with HP1 which is specific for hepatic cells. In-vitro transcription in a rat liver nuclear extract demonstrates that HP1 leads to an increased transcriptional activity. This increased transcription is specifically inhibited by the addition of an HP1-containing oligonucleotide, establishing that the interaction of factors with HP1 is essential for increased transcription. Since HP1 derived from a Xenopus gene functions in mammalian hepatocytes, we conclude that a regulatory system involved in liver-specific gene expression has been conserved during evolution.
Schorpp
M
M
Kernforschungszentrum Karlsruhe, Institut für Genetik und Toxikologie, F.R.G.
Kugler
W
W
Wagner
U
U
Ryffel
G U
GU
D000418:Albumins / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA; D008099:Liver / Q000648:ultrastructure*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors; D014162:Transfection; D014981:Xenopus / Q000235:genetics*
D000418:Albumins; D014157:Transcription Factors; D004247:DNA