Autoinduction of estrogen receptor is associated with FOSP-1 mRNA induction by estrogen in primary cultures of Xenopus oviduct cells.
The number of nuclear and cytosolic estrogen receptors (ER) per cell and the steady-state levels of the mRNA encoding a tissue-specific, estrogen-inducible protein (FOSP-1) were measured as a function of time following the addition of estradiol-17 beta (E2) to primary cultures of Xenopus oviduct cells. After a lag period of about 12 h, 10(-9) to 10(-7) M E2 caused a 10 to 15-fold increase in FOSP-1 mRNA by 60 h, whereas it was only 2-fold with 10(-7) M progesterone. Under the same conditions, E2 doubled its own total receptor content within the first 12 h, reaching a 4-fold increase in nuclear ER by 48 h. Cycloheximide treatment in the presence of 10(-7) M estradiol reduced the functional ER content by 75.90%. Treatment with the anti-estrogen ICI 164,384 of oviduct cells in which FOSP-1 mRNA was pre-induced to high levels with the hormones caused a drastic reduction in nuclear ER and a total loss of FOSP-1 mRNA in 72 h. The close correlation between the kinetics of autoinduction of ER and the induction of FOSP-1 mRNA, as was shown earlier for vitellogenin mRNA in hepatocytes (Perlman et al. (1984) Mol. Cell. Endocrinol. 38, 151-161), strongly suggests that Xenopus egg protein gene activation by estrogen requires the up-regulation of its own receptor by the hormone.
Laboratory of Developmental Biochemistry, National Institute for Medical Research, London, U.K.
B
B
Varriale
J R
JR
Tata
D000818:Animals; D002467:Cell Nucleus; D002478:Cells, Cultured; D003600:Cytosol; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D010057:Oviducts / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000494:pharmacology; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000235:genetics; D015533:Transcriptional Activation; D015854:Up-Regulation / Q000187:drug effects*; D029867:Xenopus Proteins; D014982:Xenopus laevis
D011506:Proteins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D029867:Xenopus Proteins; C065871:fosp1a protein, Xenopus; D011374:Progesterone; D004958:Estradiol