A critical role of two positively charged amino acids in the Jas motif of Arabidopsis JAZ proteins in mediating coronatine- and jasmonoyl isoleucine-dependent interactions with the COI1 F-box protein

Plant J. 2008 Sep;55(6):979-88. doi: 10.1111/j.1365-313X.2008.03566.x. Epub 2008 Jun 10.

Abstract

Coronatine is an important virulence factor produced by several pathovars of the bacterial pathogen Pseudomonas syringae. The structure of coronatine is similar to that of a class of plant hormones called jasmonates (JAs). An important step in JA signaling is the SCF(COI1) E3 ubiquitin ligase-dependent degradation of JAZ repressor proteins. We have recently shown that jasmonoyl isoleucine (JA-Ile) promotes physical interaction between Arabidopsis JAZ1 and COI1 (the F-box component of SCF(COI1)) proteins, and that the JA-Ile-dependent COI1-JAZ1 interaction could be reconstituted in yeast cells (i.e. in the absence of other plant proteins). Here we show that coronatine, but not its two biosynthetic precursors, also promotes interaction between Arabidopsis COI1 and multiple JAZ proteins. The C-terminal Jas motif, but not the N-terminal (NT) domain or central ZIM domain of JAZ proteins, is critical for JA-Ile/coronatine-dependent interaction with COI1. Two positively charged amino acid residues in the Jas domain were identified as essential for coronatine-dependent COI1-JAZ interactions. Mutations of these two residues did not affect the ability of JAZ1 and JAZ9 to interact with the transcription factor AtMYC2. Importantly, transgenic Arabidopsis plants expressing JAZ1 carrying these two mutations exhibited JA-insensitive phenotypes, including male sterility and enhanced resistance to P. syringae infection. These results not only suggest that coronatine and JA-Ile target the physical interaction between COI1 and the Jas domain of JAZ repressors, but also illustrate the critical role of positively charged amino acids in the Jas domain in mediating the JA-Ile/coronatine-dependent JAZ interaction with COI1.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Motifs
  • Amino Acids / metabolism*
  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis / microbiology
  • Arabidopsis Proteins / metabolism*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / metabolism
  • Cyclopentanes / metabolism*
  • DNA, Complementary / genetics
  • F-Box Proteins / metabolism
  • Genes, Plant
  • Indenes / metabolism*
  • Isoleucine / metabolism
  • Mutagenesis, Site-Directed
  • Mutation
  • Nuclear Proteins / metabolism*
  • Oxylipins / metabolism*
  • Phenotype
  • Plant Diseases / genetics
  • Plant Growth Regulators / metabolism
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • Protein Interaction Domains and Motifs
  • Pseudomonas Infections / genetics
  • Pseudomonas syringae / pathogenicity
  • Repressor Proteins / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Two-Hybrid System Techniques

Substances

  • Amino Acids
  • Arabidopsis Proteins
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • COI1 protein, Arabidopsis
  • Cyclopentanes
  • DNA, Complementary
  • F-Box Proteins
  • Indenes
  • JAS1 protein, Arabidopsis
  • JAZ9 protein, Arabidopsis
  • MYC2 protein, Arabidopsis
  • Nuclear Proteins
  • Oxylipins
  • Plant Growth Regulators
  • Repressor Proteins
  • Isoleucine
  • coronatine
  • jasmonic acid