Geminivirus C4 antagonizes the HIR1-mediated hypersensitive response by inhibiting the HIR1 self-interaction and promoting degradation of the protein

New Phytol. 2020 Feb;225(3):1311-1326. doi: 10.1111/nph.16208. Epub 2019 Oct 29.

Abstract

Tomato leaf curl Yunnan virus (TLCYnV)-encoded C4 protein induces the upregulation of the hypersensitive induced reaction 1 (HIR1) gene but interferes with the HIR1-mediated hypersensitive response (HR). HIR1 self-interaction is essential for the HIR1-induced HR. TLCYnV C4 impairs the HIR1 self-interaction and concomitantly increases the amount of Leucine-Rich Repeat protein 1 (LRR1), a modulator of HIR1, which binds to HIR1. LRR1 promotes the degradation of HIR1, compromising the HIR1-mediated HR. This study provides new insights into the mechanisms employed by a viral protein to counter host resistance through the cooption of the host regulatory system.

Keywords: C4; degradation; geminivirus; hypersensitive induced reaction 1; hypersensitive response; leucine-rich repeat protein 1; tomato leaf curl Yunnan virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Arabidopsis / metabolism
  • Geminiviridae / metabolism*
  • Gene Expression Regulation, Plant
  • Models, Biological
  • Mutation / genetics
  • Nicotiana / immunology
  • Nicotiana / metabolism*
  • Nicotiana / virology*
  • Plant Proteins / metabolism*
  • Protein Binding
  • Proteolysis*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Viral Proteins / metabolism*

Substances

  • Plant Proteins
  • RNA, Messenger
  • Viral Proteins