Sumoylation of Arabidopsis heat shock factor A2 (HsfA2) modifies its activity during acquired thermotholerance

Plant Mol Biol. 2010 Sep;74(1-2):33-45. doi: 10.1007/s11103-010-9652-1. Epub 2010 Jun 4.


Post-translational modification of target proteins by the small ubiquitin-like modifier protein (SUMO) regulate many cellular processes. In this work we show SUMOylation of the heat shock transcription factor, AtHsfA2, in connection with the plant's response to heat stress and acquired thermotolerance. Using the Yeast two hybrid and the bimolecular fluorescence complementation system, we have found that AtSUMO1 physically interacts with AtHsfA2. Further investigation allowed us to determine that Lys 315 of AtHsfA2 is the main SUMOylation site. Overexpression of AtSUMO1 led to a decrease in AtHsfA2 transcriptional activation of heat shock promoters. We have examined the effect of AtSUMO1 on AtHsfA2 during heat shock treatments. The phenotype of seedlings overexpressing AtSUMO1 resembled the phenotype of AtHsfA2 knock out seedlings, which were more sensitive than wild type seedlings to repeated heat treatment. Furthermore, AtSUMO1 overexpressing seedlings exhibited lower expression levels of small heat shock proteins as compared with wild type seedlings after heat treatment. Based on our findings, we suggest that AtSUMO1 is involved in the regulation of AtHsfA2 in acquired thermotolerance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism*
  • Base Sequence
  • DNA Primers / genetics
  • DNA, Plant / genetics
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Plant
  • Gene Knockout Techniques
  • Genes, Plant
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins / chemistry
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism*
  • Heat-Shock Response / genetics
  • Hot Temperature
  • Lysine / chemistry
  • Mutagenesis, Site-Directed
  • Phenotype
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified
  • Protein Interaction Domains and Motifs
  • Protein Processing, Post-Translational
  • Seedlings / genetics
  • Seedlings / metabolism
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Two-Hybrid System Techniques


  • Arabidopsis Proteins
  • DNA Primers
  • DNA, Plant
  • DNA-Binding Proteins
  • HSFA2 protein, Arabidopsis
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins
  • Plant Proteins
  • SUM1 protein, Arabidopsis
  • Transcription Factors
  • Lysine