Geminivirus-encoded TrAP suppressor inhibits the histone methyltransferase SUVH4/KYP to counter host defense.

Abstract

Transcriptional gene silencing (TGS) can serve as an innate immunity against invading DNA viruses throughout Eukaryotes. Geminivirus code for TrAP protein to suppress the TGS pathway. Here, we identified an Arabidopsis H3K9me2 histone methyltransferase, Su(var)3-9 homolog 4/Kryptonite (SUVH4/KYP), as a bona fide cellular target of TrAP. TrAP interacts with the catalytic domain of KYP and inhibits its activity in vitro. TrAP elicits developmental anomalies phenocopying several TGS mutants, reduces the repressive H3K9me2 mark and CHH DNA methylation, and reactivates numerous endogenous KYP-repressed loci in vivo. Moreover, KYP binds to the viral chromatin and controls its methylation to combat virus infection. Notably, kyp mutants support systemic infection of TrAP-deficient Geminivirus. We conclude that TrAP attenuates the TGS of the viral chromatin by inhibiting KYP activity to evade host surveillance. These findings provide new insight on the molecular arms race between host antiviral defense and virus counter defense at an epigenetic level.

• Authors: Claudia Castillo-González, Xiuying Liu, Changjun Huang, Changjiang Zhao, Zeyang Ma, Tao Hu, Feng Sun, Yijun Zhou, Xueping Zhou, Xiu-Jie Wang, Xiuren Zhang
• Journal: eLife (Elife) Vol. 4 Pg. e06671 (Sep 07 2015) ISSN: 2050-084X [Electronic] England
• PMID: 26344546 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Arabidopsis Proteins
• Viral Proteins
• Histone-Lysine N-Methyltransferase
• SUVH4 protein, Arabidopsis

Topics

• Arabidopsis (immunology, virology)
• Arabidopsis Proteins (antagonists & inhibitors)
• Geminiviridae (physiology)
• Histone-Lysine N-Methyltransferase (antagonists & inhibitors)
• Host-Pathogen Interactions
• Immune Evasion
• Protein Binding
• Protein Interaction Mapping
• Viral Proteins (metabolism)