MOLECULAR-CLONING, STRUCTURE, AND EXPRESSION OF MOUSE ESTROGEN-RESPONSIVE FINGER PROTEIN EFP - COLOCALIZATION WITH ESTROGEN-RECEPTOR MESSENGER-RNA IN TARGET ORGANS

We have previously identified a human estrogen-responsive gene, efp (e strogen-responsive finger protein), which encodes a putative transcrip tion regulator (Inoue, S., Orimo, A., Hosoi, T., Kondo, S., Toyoshima, H., Kondo, T., Ikegami, A., Ouchi, Y., Orimo, H., and Muramatsu, M. ( 1993) Proc. Natl. Acad. Sci. U. S. A. 90, 11117-11121). Here, we repor t isolation of mouse Efp cDNA and its structure containing three cyste ine-rich domains (RING finger and B1 and B2 boxes), a coiled-coil doma in, and a C-terminal domain. High levels of Efp mRNA were detected in uterus, ovary, and placenta by RNase protection assay. By in situ hybr idization histochemistry the transcripts of efp, were also detected in uterus, mammary gland, ovary, and brain, and the colocalization of Ef p and estrogen receptor mRNA was particularly demonstrated in these fe male organs. Moreover, the level of Efp mRNA in uterus and brain, whic h are known as target organs for estrogen, was up-regulated in vivo by 17 beta-estradiol. Furthermore, both the Efp and estrogen receptor mR NA were stained in the brain vesicles of 11.5-day embryos by whole mou nt in situ hybridization. These findings raise the possibility that ef p is an estrogen responsive gene that mediates estrogen action in vari ous target organs.