CpG methylation suppresses transcriptional activity of human syncytin-1 in non-placental tissues

Journal Article · Sat Apr 15 00:00:00 EDT 2006 · Experimental Cell Research

DOI:https://doi.org/10.1016/j.yexcr.2005.12.010· OSTI ID:20775356

Matouskova, Magda ^[1]; Blazkova, Jana ^[1]; Pajer, Petr ^[2]; Pavlicek, Adam ^[1]; Hejnar, Jiri ^[1]

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1. Department of Cellular and Viral Genetics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Flemingovo namisti 2, 16637 Prague 6 (Czech Republic)
2. Department of Molecular Virology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 16637 Prague (Czech Republic)

Syncytin-1 is a captive envelope glycoprotein encoded by one of human endogenous retroviruses W. It is expressed exclusively in the placental trophoblast where it participates in cell-to-cell fusion during differentiation of syncytiotrophobast. In other tissues, however, syncytin-1 expression must be kept in check because inadvertent cell fusion might be dangerous for tissue organization and integrity. We describe here an inverse correlation between CpG methylation of syncytin-1 5' long terminal repeat and its expression. Hypomethylation of the syncytin-1 5' long terminal repeat in the placenta and in the choriocarcinoma-derived cell line BeWo was detected. However, other analyzed primary cells and cell lines non-expressing syncytin-1 contain proviruses heavily methylated in this sequence. CpG methylation of syncytin-1 is resistant to the effect of the demethylating agent 5-azacytidine. The inhibitory role of CpG methylation is further confirmed by transient transfection of in-vitro-methylated syncytin-1 promoter-driven reporter construct. Altogether, we conclude that CpG methylation plays a principal role in the transcriptional suppression of syncytin-1 in non-placental tissues, and, in contrast, demethylation of the syncytin-1 promoter in trophoblast is a prerequisite for its expression and differentiation of multinucleated syncytiotrophoblast.

• OSTI ID: 20775356
• Journal Information: Experimental Cell Research, Vol. 312, Issue 7; Other Information: DOI: 10.1016/j.yexcr.2005.12.010; PII: S0014-4827(05)00604-X; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0014-4827
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
DNA
GLYCOPROTEINS
IN VITRO
INHIBITION
METHYLATION
PLACENTA
PROMOTERS