Analysis of gene structures and promoter activities of the chipmunk alpha(1)-antitrypsin-like genes.
The chipmunk hibernation-specific protein HP-55 is a component of a 140-kDa complex whose levels are drastically decreased in the blood during hibernation. It is highly homologous to alpha(1)-antitrypsin (AT). In the chipmunk, several alpha(1)-AT-like genes in addition to HP-55 (or CM55-ML) are expressed in the liver and have distinct patterns of regulation during hibernation: in hibernating chipmunks, the level of CM55-ML gene expression is greatly reduced, that of the CM55-MS gene is slightly increased, and the expression of the CM55-MM gene is hardly affected. As a first step towards understanding the hibernation-associated gene regulation of these chipmunk alpha(1)-AT-like genes, we isolated genomic clones for the CM55-ML, CM55-MM, and CM55-MS genes, and analyzed their promoter activities. These alpha(1)-AT-like genes are composed of five exons, and show a similar gene structure to that of the human alpha(1)-AT gene, suggesting that they were generated by the duplication of an ancestral alpha(1)-AT gene. Transient transfection studies using HepG2 and COS-7 cells revealed that for all three alpha(1)-AT-like genes, approximately 150-bp 5' flanking sequences were sufficient for the liver-specific promoter activity, and that the binding of HNF-1 to the promoter region could transactivate transcription. In addition, analysis of the activity of chimeric promoters composed of CM55-ML and CM55-MS gene sequences indicated that the lack of a TATA box-like sequence in the CM55-MS gene is responsible for its weak promoter activity.
Nakazawa
Asako
A
Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
Inaba
Yoko
Y
Kamijima
Atsuko
A
Kondo
Noriaki
N
Ito
Michihiko
M
Shiba
Tadayoshi
T
Takamatsu
Nobuhiko
N
D024506:5' Flanking Region / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000378:metabolism; D005091:Exons; D005796:Genes / Q000235:genetics*; D051537:Hepatocyte Nuclear Factor 1; D051538:Hepatocyte Nuclear Factor 1-alpha; D006801:Humans; D007438:Introns; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012589:Sciuridae / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000378:metabolism; D024363:Transcription Initiation Site; D014158:Transcription, Genetic; D014162:Transfection; D000515:alpha 1-Antitrypsin / Q000235:genetics*
D004268:DNA-Binding Proteins; C496487:HNF1A protein, human; D051538:Hepatocyte Nuclear Factor 1-alpha; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D000515:alpha 1-Antitrypsin; D051537:Hepatocyte Nuclear Factor 1; D004247:DNA; D008156:Luciferases