Molecular cloning of estrogen receptor alpha (ERalpha; ESR1) of the Japanese giant salamander, Andrias japonicus.
Estrogens are essential for normal reproductive activity in females and males and for ovarian differentiation during a critical developmental stage in many vertebrates. To understand the molecular mechanisms of estrogen action and to evaluate estrogen receptor ligand interactions in the Japanese giant salamander (Andrias japonicus), we isolated cDNA encoding the estrogen receptor (ER) from the liver. A full-length Japanese giant salamander ER cDNA (jgsER) was obtained using 5' and 3' rapid amplification cDNA ends (RACE). The deduced amino acid sequence of the jgsER showed high identity to the Xenopus ERalpha (ESR1) (77.7%). We have applied both the conventional ERE-luciferase reporter assay system and the GAL4-transactivation system to characterize this receptor. In two different transient transfection assay systems using mammalian cells, the jgsER protein displayed estrogen-dependent activation of transcription. The GAL4-transactivation system showed about 10-fold greater activity of the estrogen receptor by hormone when compared to the conventional ERE-luciferase reporter assay system. Tissue distribution of ERalpha mRNA was examined and kidney, ovary and liver exhibited expression. This is the first isolation of an estrogen receptor from a salamander and also is the first functional cDNA obtained from the Japanese giant salamander, an endangered species considered a special natural monument of Japan.
Katsu
Yoshinao
Y
Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Aichi, Japan.
Kohno
Satomi
S
Oka
Tomohiro
T
Mitsui
Naoko
N
Tooi
Osamu
O
Santo
Noriaki
N
Urushitani
Hiroshi
H
Fukumoto
Yukio
Y
Kuwabara
Kazushi
K
Ashikaga
Kazuhide
K
Minami
Shinji
S
Kato
Shigeaki
S
Ohta
Yasuhiko
Y
Guillette
Louis J
LJ
Iguchi
Taisen
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D003001:Cloning, Molecular / Q000379:methods*; D006224:Cricetinae; D047628:Estrogen Receptor alpha / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005260:Female; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D015533:Transcriptional Activation; D014162:Transfection; D014562:Caudata / Q000235:genetics*
D047628:Estrogen Receptor alpha