Changes of liver-enriched nuclear transcription factors for albumin gene in starvation in rats.
The regulatory mechanism of albumin gene transcription was examined using male Donryu rats (7 wk old) starved for 1 or 3 d. At the designated times, the rats were sacrificed to harvest the liver and to measure the serum albumin level. Neither the serum albumin nor the albumin messenger RNA (mRNA) level showed a significant change for these starvation periods. Among nuclear factors binding to the D site of albumin gene promoter, the CCAAT/enhancer binding protein alpha (C/EBP alpha) mRNA level showed a decrease and the D site binding protein (DBP) mRNA level tended to decrease after 3 d of starvation. In contrast, the C/EBP beta mRNA level showed a significant increase at day 1. As a B site binding nuclear factor, the hepatocyte nuclear factor 1 (HNF-1) mRNA level significantly increased at day 1. Gel mobility-shift analysis combined with Western immunoblotting confirmed the presence of D site binding proteins composed of DBP and C/EBP alpha and beta in both groups subjected to oral feeding and to 3-d starvation, though quantitative analysis could not be done. In conclusion, the nuclear transcription factors binding to the albumin gene promoter undergo regulatory changes during 3 d of starvation, whereas there is no significant decrease in the albumin mRNA level.
Ogawa
A
A
Department of Surgery II, Osaka University Medical School, Japan.
Tsujinaka
T
T
Yano
M
M
Morita
S
S
Taniguchi
M
M
Kaneko
K
K
Doki
Y
Y
Shiozaki
H
H
Monden
M
M
D000418:Albumins / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D022762:CCAAT-Enhancer-Binding Proteins; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D015536:Down-Regulation; D004742:Enhancer Elements, Genetic; D008099:Liver / Q000378:metabolism*; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012709:Serum Albumin / Q000378:metabolism; D013217:Starvation / Q000097:blood / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D000418:Albumins; D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D012709:Serum Albumin; D014157:Transcription Factors; D004247:DNA