A DNA methylation reader complex that enhances gene transcription.

Area of Science:

• Plant molecular biology
• Epigenetics
• Gene regulation

Background:

• DNA methylation typically represses gene expression but can also activate it.
• The downstream factors mediating these effects are largely unknown.
• Understanding these factors is crucial for deciphering gene regulation.

Purpose of the Study:

• To identify proteins that interact with methylated DNA in Arabidopsis thaliana.
• To elucidate the function of these methyl-binding proteins in gene expression.
• To investigate the mechanism by which DNA methylation influences gene transcription.

Main Methods:

• Comparative interactomics to isolate proteins associated with methylated DNA.
• In vitro binding assays to confirm DNA methylation binding.
• In vivo association studies with euchromatic methylation.
• Complex formation analysis with DNAJ domain-containing proteins.

Main Results:

• Two SU(VAR)3-9 homologs, SUVH1 and SUVH3, were identified as methyl-binding proteins.
• SUVH1 and SUVH3 bind methylated DNA and associate with euchromatic methylation.
• These proteins form a complex with DNAJ1 and DNAJ2.
• Ectopic expression of DNAJ1 enhanced gene transcription across different species.

Conclusions:

• SUVH proteins bind methylated DNA and recruit DNAJ proteins.
• This interaction enhances proximal gene expression.
• The SUVH-DNAJ complex counteracts the repressive effects of transposon insertions near genes.