Liver receptor homologue-1 (LRH-1) activates the promoter of brain aromatase (cyp19a2) in a teleost fish, the medaka, Oryzias latipes.
The medaka, Oryzias latipes, like other fish, have two distinct aromatase genes, the ovarian (cyp19a1) and brain (cyp19a2) forms. We previously reported that Ad4BP/SF-1, a member of the NR5A subfamily, plays an important role in the regulation of cyp19a1 expression in medaka ovarian follicles during vitellogenesis. In the present study, we investigated whether liver receptor homologue-1 (LRH-1), another NR5A subfamily member, is involved in the regulation of cyp19a2 expression in the medaka brain. In situ hybridization analysis revealed that LRH-1 was expressed in the hypothalamus, where it colocalized with aromatase (cyp19a2). We then showed by transient transfection assays that LRH-1 was able to increase expression of a cyp19a2 reporter gene in various mammalian cell lines, and that mutation of a putative LRH-1 binding site within the cyp19a2 promoter abolished this effect. Taken together, these findings suggest that LRH-1 plays a role in regulating cyp19a2 expression in the medaka brain. This is the first to demonstrate in vitro the activation of brain aromatase by LRH-1 in the vertebrate brain.
Ohmuro-Matsuyama
Yuki
Y
Department of Basic Biology, The Graduate University for Advanced Studies, Okazaki, Japan.
Okubo
Kataaki
K
Matsuda
Masaru
M
Ijiri
Shigeho
S
Wang
Deshou
D
Guan
Guijun
G
Suzuki
Taiga
T
Matsuyama
Makoto
M
Morohashi
Ken-Ichiro
K
Nagahama
Yoshitaka
Y
D000818:Animals; D001141:Aromatase / Q000032:analysis / Q000235:genetics*; D001483:Base Sequence; D001921:Brain / Q000201:enzymology*; D002460:Cell Line; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008969:Molecular Sequence Data; D009990:Oryzias / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D015534:Trans-Activators / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D024363:Transcription Initiation Site
D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D015534:Trans-Activators; D001141:Aromatase