Amino acid regulation of gene transcription of rat insulin-like growth factor-binding protein-1.
To investigate the molecular mechanisms of increased transcription of the insulin-like growth factor-binding protein-1 (IGFBP-1) gene in dietary protein-deprived animals, the cis-acting sequence that is involved in this regulation was analyzed. We first showed that IGFBP-1 gene transcription was up-regulated by amino acid deprivation in cultured liver cell lines: H4IIE and HuH-7. Since HuH-7 cells showed a greater increase in IGFBP-1 mRNA in response to amino acid deprivation, this cell line was used in further experiments. Using a promoter function assay, we found that up-regulation of promoter activity responding to amino acid deprivation was abolished by deleting the region between -112 and -81 bp from the cap site from the gene construct. This cis-acting region includes the insulin-responsive element (IRE) and glucocorticoid responsive element (GRE) of IGFBP-1. In summary, the present observation suggests that the 32-bp (-112 to -81) in the IGFBP-1 gene 5' promoter region is involved in the induction of the IGFBP-1 gene in response to amino acid deprivation.
Takenaka
A
A
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan.
Komori
K
K
Morishita
T
T
Takahashi
S I
SI
Hidaka
T
T
Noguchi
T
T
D000596:Amino Acids / Q000502:physiology*; D000818:Animals; D015152:Blotting, Northern; D006528:Carcinoma, Hepatocellular; D015870:Gene Expression; D005809:Genes, Regulator; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D014407:Tumor Cells, Cultured
D000596:Amino Acids; D018970:Insulin-Like Growth Factor Binding Protein 1; D012333:RNA, Messenger