Abstract
Transcriptional coactivators, CREB-binding protein (CBP) and p300, exhibit high homology in structure and similar functions. In the present study, we analyzed the function of CBP and p300 proteins as transcriptional coactivators in the expression of albumin in hepatocytes. The expression levels of CBP and p300 were high in fetal hepatocytes, but low in adult ones. Immunoprecipitation assays showed that both CBP and p300 interacted with hepatocyte nuclear factor-1α (HNF-1α) in primary hepatocytes. Furthermore, CBP and p300 were co-precipitated without HNF-1α. Chromatin immunoprecipitation (ChIP) assays revealed that both CBP and p300 are located in the albumin promoter region in hepatocytes. These results suggested that HNF-1α, CBP and p300 were incorporated into a preinitiation complex of RNA polymerase II at the albumin promoter. Luciferase reporter assays showed that CBP and p300 cooperatively triggered HNF-1α-mediated transcription of the albumin promoter. In addition, inhibition of CBP or p300 using small interfering RNAs (siRNAs) resulted in a reduction in albumin expression. These results suggest that both CBP and p300 are required for enhanced expression of albumin.
| Original language | English |
|---|---|
| Pages (from-to) | 313-319 |
| Number of pages | 7 |
| Journal | Journal of Biochemistry |
| Volume | 136 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Sep 1 2004 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Biochemistry
Cite this
Transcriptional coactivators CBP and p300 cooperatively enhance HNF-1α-mediated expression of the albumin gene in hepatocytes. / Dohda, Takeaki; Kaneoka, Hidenori; Inayoshi, Yujin; Kamihira, Masamichi; Miyake, Katsuhide; Iijima, Shinji.
In: Journal of Biochemistry, Vol. 136, No. 3, 01.09.2004, p. 313-319.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Transcriptional coactivators CBP and p300 cooperatively enhance HNF-1α-mediated expression of the albumin gene in hepatocytes
AU - Dohda, Takeaki
AU - Kaneoka, Hidenori
AU - Inayoshi, Yujin
AU - Kamihira, Masamichi
AU - Miyake, Katsuhide
AU - Iijima, Shinji
PY - 2004/9/1
Y1 - 2004/9/1
N2 - Transcriptional coactivators, CREB-binding protein (CBP) and p300, exhibit high homology in structure and similar functions. In the present study, we analyzed the function of CBP and p300 proteins as transcriptional coactivators in the expression of albumin in hepatocytes. The expression levels of CBP and p300 were high in fetal hepatocytes, but low in adult ones. Immunoprecipitation assays showed that both CBP and p300 interacted with hepatocyte nuclear factor-1α (HNF-1α) in primary hepatocytes. Furthermore, CBP and p300 were co-precipitated without HNF-1α. Chromatin immunoprecipitation (ChIP) assays revealed that both CBP and p300 are located in the albumin promoter region in hepatocytes. These results suggested that HNF-1α, CBP and p300 were incorporated into a preinitiation complex of RNA polymerase II at the albumin promoter. Luciferase reporter assays showed that CBP and p300 cooperatively triggered HNF-1α-mediated transcription of the albumin promoter. In addition, inhibition of CBP or p300 using small interfering RNAs (siRNAs) resulted in a reduction in albumin expression. These results suggest that both CBP and p300 are required for enhanced expression of albumin.
AB - Transcriptional coactivators, CREB-binding protein (CBP) and p300, exhibit high homology in structure and similar functions. In the present study, we analyzed the function of CBP and p300 proteins as transcriptional coactivators in the expression of albumin in hepatocytes. The expression levels of CBP and p300 were high in fetal hepatocytes, but low in adult ones. Immunoprecipitation assays showed that both CBP and p300 interacted with hepatocyte nuclear factor-1α (HNF-1α) in primary hepatocytes. Furthermore, CBP and p300 were co-precipitated without HNF-1α. Chromatin immunoprecipitation (ChIP) assays revealed that both CBP and p300 are located in the albumin promoter region in hepatocytes. These results suggested that HNF-1α, CBP and p300 were incorporated into a preinitiation complex of RNA polymerase II at the albumin promoter. Luciferase reporter assays showed that CBP and p300 cooperatively triggered HNF-1α-mediated transcription of the albumin promoter. In addition, inhibition of CBP or p300 using small interfering RNAs (siRNAs) resulted in a reduction in albumin expression. These results suggest that both CBP and p300 are required for enhanced expression of albumin.
UR - http://www.scopus.com/inward/record.url?scp=9144253197&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=9144253197&partnerID=8YFLogxK
U2 - 10.1093/jb/mvh123
DO - 10.1093/jb/mvh123
M3 - Article
C2 - 15598887
AN - SCOPUS:9144253197
VL - 136
SP - 313
EP - 319
JO - Journal of Biochemistry
JF - Journal of Biochemistry
SN - 0021-924X
IS - 3
ER -