Identification of the transactivating region of the homeodomain protein, hex.
The homeodomain-containing protein Hex acts as an activator as well as a repressor of transcription in animals. While its repression domain has been mapped to the amino-terminal region, the activation domain has never been identified. Here, we show that the homeodomain and the acidic carboxyl-terminal region are necessary for full activation of the sodium-dependent bile acid cotransporter gene promoter in a cell type-independent manner, suggesting that the carboxyl-terminal region comprising residues 197 to 271 functions as the activation domain. In addition, we observed that a Hex mutant without this activation domain acts as a dominant-negative mutant as to the transactivating function of Hex.
Kasamatsu
Shinya
S
Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601.
Sato
Ayuko
A
Yamamoto
Taichi
T
Keng
Vincent W
VW
Yoshida
Hiroshi
H
Yamazaki
Yuka
Y
Shimoda
Masafumi
M
Miyazaki
Jun-ichi
J
Noguchi
Tamio
T
D000818:Animals; D001483:Base Sequence; D001647:Bile Acids and Salts / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012964:Sodium / Q000494:pharmacology; D014157:Transcription Factors / Q000502:physiology; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D001647:Bile Acids and Salts; D018398:Homeodomain Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D012964:Sodium; D008156:Luciferases