Endometrial biology is characterized by programmed proliferation and differentiation that is synchronous with ovarian folliculogenesis to maximize the chance of pregnancy. Glycodelin-A, an endometrial secretory protein, promotes pregnancy mostly through immunomodulatory mechanisms. Glycodelin-A is repressed during the proliferative and early secretory phase and activated thereafter. Progesterone activates glycodelin via the Sp1 (Specificity Protein 1) transactivator. We identify a novel role for Kruppel-like transcription factor 11 (KLF11) as a glycodelin-A repressor. Although KLF11 bound 2 distinct regulatory elements, it regulated glycodelin promoter activity differentially through each element. Whereas KLF11 weakly activated glycodelin promoter activity via a region that also bound Sp1, the dominant effect of KLF11 was repression of promoter activity, messenger RNA (mRNA), and protein expression via a novel, specific binding element. KLF11 mediated this repression by recruiting the SIN3/histone deacetylase (HDAC) corepressor complex to the glycodelin promoter. KLF11 may solely, or by competing with Sp1, repress glycodelin-A levels and thereby influence its role in the endometrium.
Keywords: KLF11; SIN3/HDAC; endometrium; glycodelin-A; repressor.