An embryonic demethylation mechanism involving binding of transcription factors to replicating DNA

An embryonic demethylation mechanism involving binding of transcription factors to replicating DNA In vertebrates, transcriptionally active promoters are undermethylated. Since the transcription factor Sp1, and more recently NF‐κB, have been implicated in the demethylation process, we examined the effect of transcription factors on demethylation by injecting in vitro methylated plasmid DNA into Xenopus fertilized eggs. We found that various transactivation domains, including a strong acidic activation domain from the viral protein VP16, can enhance demethylation of a promoter region when fused to a DNA binding domain which recognizes the promoter. Furthermore, demethylation occurs only after the midblastula transition, when the general transcription machinery of the host embryo becomes available. Nevertheless, transcription factor binding need not be followed by actual transcription, since demethylation is not blocked by α‐amanitin treatment. Finally, replication of the target DNA is a prerequisite for efficient demethylation since only plasmids that carry the bovine papilloma virus sequences which support plasmid replication after the midblastula transition are demethylated. No demethylation is detectable in the oocyte system where DNA is not replicated. These results suggest that, in the Xenopus embryo, promoters for which transcription factors are available are demethylated by a replication‐dependent, possibly passive mechanism. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The EMBO Journal Wiley

An embryonic demethylation mechanism involving binding of transcription factors to replicating DNA

Loading next page...
 
/lp/wiley/an-embryonic-demethylation-mechanism-involving-binding-of-F7Yt346aWa
Publisher
Wiley
Copyright
Copyright © 2013 Wiley Periodicals, Inc
ISSN
0261-4189
eISSN
1460-2075
D.O.I.
10.1093/emboj/17.5.1446
Publisher site
See Article on Publisher Site

Abstract

In vertebrates, transcriptionally active promoters are undermethylated. Since the transcription factor Sp1, and more recently NF‐κB, have been implicated in the demethylation process, we examined the effect of transcription factors on demethylation by injecting in vitro methylated plasmid DNA into Xenopus fertilized eggs. We found that various transactivation domains, including a strong acidic activation domain from the viral protein VP16, can enhance demethylation of a promoter region when fused to a DNA binding domain which recognizes the promoter. Furthermore, demethylation occurs only after the midblastula transition, when the general transcription machinery of the host embryo becomes available. Nevertheless, transcription factor binding need not be followed by actual transcription, since demethylation is not blocked by α‐amanitin treatment. Finally, replication of the target DNA is a prerequisite for efficient demethylation since only plasmids that carry the bovine papilloma virus sequences which support plasmid replication after the midblastula transition are demethylated. No demethylation is detectable in the oocyte system where DNA is not replicated. These results suggest that, in the Xenopus embryo, promoters for which transcription factors are available are demethylated by a replication‐dependent, possibly passive mechanism.

Journal

The EMBO JournalWiley

Published: Mar 2, 1998

References

  • Differential sensitivity of zinc finger transcription factors MTF‐1, Sp1, and Krox‐20 to CpG methylation of their binding sites
    Radtke, Radtke; Hug, Hug; Georgiev, Georgiev; Matsuo, Matsuo; Schaffner, Schaffner
  • Different potential of cellular and viral activators of transcription revealed in oocytes and early embryos of Xenopus laevis
    Xu, Xu; Rungger, Rungger; Georgiev, Georgiev; Seipel, Seipel; Schaffner, Schaffner

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create folders to
organize your research

Export folders, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off