The analysis of the human hemopexin promoter defines a new class of liver-specific genes.
Hemopexin (Hpx) is a plasma glycoprotein which is expressed only in the liver. It is synthesized at a lower rate in the fetal liver than in the adult, and its level increases during acute infections. As shown here, a fragment of the human hemopexin promoter spanning from positions -130 to +22 relative to the cap site is sufficient to direct cell-specific transcription of a reporter gene. Within this segment a short sequence, located between positions -120 and -104, is responsible for this effect. This positive cis-acting element, the Hpx A site, interacts with a family of nuclear proteins, some of which are present only in hepatoma cells. The potential meaning of these complex DNA-protein interactions and the homology with elements present on the promoter of other liver-specific and acute phase genes are discussed.
Poli
V
V
European Molecular Biology Laboratory, Heidelberg, FRG.
Silengo
L
L
Altruda
F
F
Cortese
R
R
D001483:Base Sequence; D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D002872:Chromosome Deletion; D005796:Genes; D006367:HeLa Cells / Q000378:metabolism; D006466:Hemopexin / Q000235:genetics*; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008113:Liver Neoplasms; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D011401:Promoter Regions, Genetic; D013698:Templates, Genetic
D006466:Hemopexin