Epigenetic regulation of the maize Spm transposable element: Novel activation of a methylated promoter by TnpA

Michael Schläppi, Ramesh Raina, Nina Fedoroff

Research output: Contribution to journalArticle

70 Scopus citations

Abstract

Spm is epigenetically inactivated by C-methylation near its transcription start site. We have investigated the interaction between TnpA, an autoregulatory protein that can reactivate a silent Spm, and the promoter of the element. The promoter undergoes rapid de novo methylation and inactivation in stably transformed plants, but only if it includes a GC-rich sequence downstream of the promoter. TnpA activates the inactive, methylated promoter and leads to reduced methylation. By contrast, TnpA represses the active, unmethylated Spm promoter. Only the internal DNA-binding and dimerization domains of the protein are required for repression, while activation requires an additional C-terminal sequence. TnpA is therefore a unique regulatory protein with a conventional transcriptional repressor activity and a novel ability to activate a methylated, inactive promoter.

Original languageEnglish (US)
Pages (from-to)427-437
Number of pages11
JournalCell
Volume77
Issue number3
DOIs
StatePublished - May 6 1994
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Fingerprint Dive into the research topics of 'Epigenetic regulation of the maize Spm transposable element: Novel activation of a methylated promoter by TnpA'. Together they form a unique fingerprint.

  • Cite this