Journal Article

A DNA methylation reader complex that enhances gene transcription

Harris, C. Jake, Wang, Zonghua, Zhong, Zhenhui, Cornett, Evan M., Liu, Wanlu, Scheibe, Marion, Du, Jiamu, Gallego-Bartolome, Javier, Yen, Linda, Chen, Wei, Rayatpisheh, Shima, Wongpalee, Somsakul Pop, Rothbart, Scott B., Wohlschlegel, James A., Li, Xueqin, Groth, Martin, Vaughan, Robert M., Jacobsen, Steven E., Butter, Falk, Xue, Yan, Barshop, William D.

2018

Overview

DNA methylation generally represses transcription, but in some instances, it has also been implicated in transcription activation. Harris et al. identified a protein complex in Arabidopsis that is recruited to chromatin by DNA methylation. This complex specifically activated the transcription of genes that are already mildly transcribed but had no effect on transcriptionally silent genes such as transposable elements. The complex thereby counteracts the repression effect caused by transposon insertion in neighboring genes while leaving transposons silent. Thus, by balancing both repressive and activating transcriptional effects, DNA methylation can act to fine-tune gene expression. Science , this issue p. 1182 A protein complex that binds methylated DNA can counteract the repressive effects of transposon invasion on neighboring gene expression. DNA methylation generally functions as a repressive transcriptional signal, but it is also known to activate gene expression. In either case, the downstream factors remain largely unknown. By using comparative interactomics, we isolated proteins in Arabidopsis thaliana that associate with methylated DNA. Two SU(VAR)3-9 homologs, the transcriptional antisilencing factor SUVH1, and SUVH3, were among the methyl reader candidates. SUVH1 and SUVH3 bound methylated DNA in vitro, were associated with euchromatic methylation in vivo, and formed a complex with two DNAJ domain-containing homologs, DNAJ1 and DNAJ2. Ectopic recruitment of DNAJ1 enhanced gene transcription in plants, yeast, and mammals. Thus, the SUVH proteins bind to methylated DNA and recruit the DNAJ proteins to enhance proximal gene expression, thereby counteracting the repressive effects of transposon insertion near genes.

• Publisher: The American Association for the Advancement of Science
• Subject: Arabidopsis - enzymology / Arabidopsis - genetics / Arabidopsis Proteins - metabolism / Chromatin / Deoxyribonucleic acid / DNA / DNA Methylation / Gene expression / Gene Expression Regulation, Plant / Genes / Histone-Lysine N-Methyltransferase - metabolism / Homology / HSP40 Heat-Shock Proteins - chemistry / HSP40 Heat-Shock Proteins - metabolism / Insertion / Methyltransferases - metabolism / Protein Domains / Proteins / Transcription activation / Transcription, Genetic / Transposons / Yeast