Nuclear factor 1 family proteins bind to the silencer element in the rat glutathione transferase P gene.
We have previously identified a silencer region in the glutathione transferase P (GST-P) gene, of which the expression is completely repressed in liver of the rat. At least three trans-acting factors bind to multiple cis-elements in this region. Since GST-P silencer 4 (GSP4) is a dominant element in this silencer, we purified the GSP4 binding protein, called Silencer Factor A (SF-A). Purified SF-A was separated into several proteins on an SDS-polyacrylamide gel, and the amino acid sequences of four major components of SF-A were determined. The amino acid sequences of three fragments were identical to those of rat NF1-L, and that of the other fragment was the same as that of hamster NF1/Red1. It is known that nuclear factor 1 (NF1) family proteins are encoded by at least four independent genes in vertebrates, and NF1-L and NF1/Red1 are derived from different genes, NFI-A and NFI-B, respectively. The microsequencing of SF-A revealed that at least two types of NF1 existed in rat liver. Functional analysis by using GAL4-fusion protein in HepG2 cells revealed that NFI-A represented the transcription activity from human metallothionein IIA promoter. Our findings indicate that multiple forms of the NF1 family bind to the silencer region and contribute to the negative regulation of the GST-P gene expression.
Osada
S
S
Department of Environmental Biochemistry, Faculty of Pharmaceutical Sciences, Osaka University.
Daimon
S
S
Ikeda
T
T
Nishihara
T
T
Yano
K
K
Yamasaki
M
M
Imagawa
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D002467:Cell Nucleus / Q000737:chemistry; D006224:Cricetinae; D004247:DNA / Q000378:metabolism*; D018076:DNA, Complementary / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism*; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D008099:Liver / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic; D051381:Rats; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D007527:Isoenzymes; D051839:NFI Transcription Factors; C497592:NFIA protein, human; C106508:Nfia protein, rat; D009687:Nuclear Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D004247:DNA; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase; C496558:Gstp1 protein, rat