TY - JOUR
T1 - Regulation of the human protein C inhibitor gene expression in HepG2 cells
T2 - Role of Sp1 and AP2
AU - Hayashi, Tatsuya
AU - Usui, Masanobu
AU - Nishioka, Junji
AU - Zhang, Zu Xun
AU - Suzuki, Koji
PY - 1998/6/1
Y1 - 1998/6/1
N2 - Protein C inhibitor (PCI) is the plasma inhibitor of activated protein C, which is the main protease of the anticoagulant protein C pathway. In this study the transcriptional regulation of human PCI gene in the human hepatoma cell line, HepG2, was characterized by evaluating the transient expression of a luciferase reporter gene. The 5' Banking region (residues -1587 to +2) of the PCI gene showed an adequate transcriptional activity, the maximum transcriptional activity being in a region between residues -452 and -94, which contains an Sp1-binding site, two AP2-binding sites and an inverted AP2-binding site. Transient expression assays with various deletion mutants and site-directed mutants showed that the Sp1-binding site (residues -302 to -294) has a potent promoter activity and that the upstream AP2-binding site (residues -350 to -343) has a potent enhancer activity; no activity was detected in the inverted (residues -413 to -404) and downstream (residues -136 to -127) AP2-binding sites. In addition, a region of the PCI gene (residues -452 to -414) containing the STATx-binding site, the A-activator (AA)-binding site, and the interferon α (IFN-α) response element, and another region of the PCI gene (residues -176 to -147) containing the GATA-1 and the IFN-γ response element showed potent silencer activities. Gel mobility-shift assays with various DNA fragments indicated that the Sp1-binding site, the upstream AP2-binding site, the AA-binding site and the IFN-γ response element interact with nuclear protein(s) of HepG2 cells. These findings suggest that the Sp1-binding site is the promoter, the AP2-binding site (residues -350 to -343) the enhancer, and both the AA-binding site and the IFN-γ response element are the silencers of human PCI gene expression in HepG2 cells.
AB - Protein C inhibitor (PCI) is the plasma inhibitor of activated protein C, which is the main protease of the anticoagulant protein C pathway. In this study the transcriptional regulation of human PCI gene in the human hepatoma cell line, HepG2, was characterized by evaluating the transient expression of a luciferase reporter gene. The 5' Banking region (residues -1587 to +2) of the PCI gene showed an adequate transcriptional activity, the maximum transcriptional activity being in a region between residues -452 and -94, which contains an Sp1-binding site, two AP2-binding sites and an inverted AP2-binding site. Transient expression assays with various deletion mutants and site-directed mutants showed that the Sp1-binding site (residues -302 to -294) has a potent promoter activity and that the upstream AP2-binding site (residues -350 to -343) has a potent enhancer activity; no activity was detected in the inverted (residues -413 to -404) and downstream (residues -136 to -127) AP2-binding sites. In addition, a region of the PCI gene (residues -452 to -414) containing the STATx-binding site, the A-activator (AA)-binding site, and the interferon α (IFN-α) response element, and another region of the PCI gene (residues -176 to -147) containing the GATA-1 and the IFN-γ response element showed potent silencer activities. Gel mobility-shift assays with various DNA fragments indicated that the Sp1-binding site, the upstream AP2-binding site, the AA-binding site and the IFN-γ response element interact with nuclear protein(s) of HepG2 cells. These findings suggest that the Sp1-binding site is the promoter, the AP2-binding site (residues -350 to -343) the enhancer, and both the AA-binding site and the IFN-γ response element are the silencers of human PCI gene expression in HepG2 cells.
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U2 - 10.1042/bj3320573
DO - 10.1042/bj3320573
M3 - Article
C2 - 9601089
AN - SCOPUS:0032103561
SN - 0264-6021
VL - 332
SP - 573
EP - 582
JO - Biochemical Journal
JF - Biochemical Journal
IS - 2
ER -