Cell Stress and Chaperones

, Volume 13, Issue 2, pp 183–197

The plant sHSP superfamily: five new members in Arabidopsis thaliana with unexpected properties

  • Masood Siddique
  • Sascha Gernhard
  • Pascal von Koskull-Döring
  • Elizabeth Vierling
  • Klaus-Dieter Scharf
Original Paper

DOI: 10.1007/s12192-008-0032-6

Cite this article as:
Siddique, M., Gernhard, S., von Koskull-Döring, P. et al. Cell Stress and Chaperones (2008) 13: 183. doi:10.1007/s12192-008-0032-6

Abstract

The small heat shock proteins (sHsps), which are ubiquitous stress proteins proposed to act as chaperones, are encoded by an unusually complex gene family in plants. Plant sHsps are classified into different subfamilies according to amino acid sequence similarity and localization to distinct subcellular compartments. In the whole Arabidopsis thaliana genome, 19 genes were annotated to encode sHsps, of which 14 belong to previously defined plant sHsp families. In this paper, we report studies of the five additional sHsp genes in A. thaliana, which can now be shown to represent evolutionarily distinct sHsp subfamilies also found in other plant species. While two of these five sHsps show expression patterns typical of the other 14 genes, three have unusual tissue specific and developmental profiles and do not respond to heat induction. Analysis of intracellular targeting indicates that one sHsp represents a new class of mitochondrion-targeted sHsps, while the others are cytosolic/nuclear, some of which may cooperate with other sHsps in formation of heat stress granules. Three of the five new proteins were purified and tested for chaperone activity in vitro. Altogether, these studies complete our basic understanding of the sHsp chaperone family in plants.

Keywords

Heat stressSmall heat shock proteinsChaperonesStress granulesPlants

Supplementary material

12192_2008_32_MOESM1_ESM.pdf (264 kb)
Fig. S1A Cytoplasmic/nuclear subfamily CIV. B Cytoplasmic/nuclear subfamily CV. C Cytoplasmic/nuclear subfamily CVI. D Mitochondrial subfamily MII. E Peroxisomal subfamily (Po) (PDF 237 KB)
12192_2008_32_MOESM2_ESM.pdf (478 kb)
Fig. S2A Hsp17.6C-CI. B Hsp18.5-CIV. C Hsp21.7-CVI. D Hsp26.5-MIIΔTP. E Hsp15.7-Po (PDF 476 KB)
12192_2008_32_MOESM3_ESM.pdf (511 kb)
Fig. S3A Nucleo-cytoplasmic sHsps. B Organellar sHsps (PDF 508 KB)
12192_2008_32_MOESM4_ESM.doc (48 kb)
Table S1Overview of sHsp expression constructs and used primers (DOC 49 KB)
12192_2008_32_MOESM5_ESM.doc (41 kb)
Table S2Overview of microarray elements for expression analysis of sHsps (DOC 42 KB)
12192_2008_32_MOESM6_ESM.doc (131 kb)
Table S3sHsps homologous to the newly identified A.thaliana members (DOC 147 KB)

Copyright information

© Cell Stress Society International 2008

Authors and Affiliations

  • Masood Siddique
    • 1
    • 3
  • Sascha Gernhard
    • 1
    • 3
  • Pascal von Koskull-Döring
    • 1
  • Elizabeth Vierling
    • 2
  • Klaus-Dieter Scharf
    • 1
  1. 1.Molecular Cell BiologyJohann Wolfgang Goethe UniversityFrankfurt am MainGermany
  2. 2.Department of Biochemistry and Molecular BiophysicsUniversity of ArizonaTucsonUSA
  3. 3.Department of Biochemistry II, University HospitalJohann Wolfgang Goethe UniversityFrankfurt am MainGermany