Local expression of a POU family transcription factor, Pit-1, in the rat placenta.
A pituitary-specific trans-acting factor, Pit-1 regulates transcriptional activity of growth hormone (GH) and prolactin (PRL) genes. Pit-1 can bind and activate the promoters of human chorionic somatomammotropin (hCS-A) and placental GH variants (hGH-V) as well. However, expression of Pit-1 in the rat placenta has not yet been elucidated. The present study aims to determine whether the Pit-1 gene is locally expressed in the rat placenta using reverse transcription-polymerase chain reaction (RT-PCR), Northern blot and Western blot hybridization, in situ hybridization and immunohistochemistry. PCR products were further analyzed by Southern hybridization and DNA sequencing. The estimated size of Pit-1 mRNA in placenta was very similar to that in anterior pituitary (AP). PCR products from placenta were exactly the same size with that from AP and confirmed as Pit-1-specific by Southern hybridization. The Pit-1 specific sequence was also confirmed by sequencing of partial amplification fragments. Immunoreactive 33 kDa Pit-1 was present in the placenta as well as in AP. Pit-1 specific mRNA and protein were localized in the trophoblast cells of placenta. These data suggest that Pit-1 is locally synthesized in the rat placenta and may be involved in the regulation of GH- and/or PRL-like gene expression in the placenta.
Lee
B J
BJ
Department of Biology, College of Natural Sciences, University of Ulsan, South Korea.
Jeong
J K
JK
Kim
J H
JH
Kang
S G
SG
Kim
M O
MO
Choi
W S
WS
D000818:Animals; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger; D051381:Rats; D017207:Rats, Sprague-Dawley; D050817:Transcription Factor Pit-1; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C494186:Pou1f1 protein, rat; D012333:RNA, Messenger; D050817:Transcription Factor Pit-1; D014157:Transcription Factors