Evolution and Diversity of Prokaryotic Small Heat Shock Proteins

Kappé, Guido; Leunissen, Jack A. M.; Jong, Wilfried W. de

doi:10.1007/978-3-642-56348-5_1

Cited by 86 publications

(70 citation statements)

References 29 publications

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“…DISCUSSION sHsps differ from other molecular chaperones in several aspects. The most important are the efficient binding of several non-native polypeptide chains in one chaperone complex and the dynamics of the quaternary structure (3,8).…”

Section: Stability Of Hsp26⅐substratementioning

confidence: 99%

“…Specifically, members of the groups of small heat shock proteins (sHsps) 1 exhibit an astounding binding capacity for unfolded polypeptides (2)(3)(4)(5)(6)(7). sHsps have been found in almost all organisms studied (8).…”

mentioning

confidence: 99%

“…sHsps are characterized by a conserved C-terminal ␣-crystallin domain and subunit masses between 15 and 40 kDa (2,3,5). This implies that the N-terminal parts are heterogeneous in size and sequence.…”

mentioning

confidence: 99%

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Analysis of the Regulation of the Molecular Chaperone Hsp26 by Temperature-induced Dissociation

Stromer¹,

Fischer

Richter

et al. 2004

Journal of Biological Chemistry

122

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Small heat shock proteins (sHsps) are molecular chaperones that efficiently bind non-native proteins. All members of this family investigated so far are oligomeric complexes. For Hsp26, an sHsp from the cytosol of Saccharomyces cerevisiae, it has been shown that at elevated temperatures the 24-subunit complex dissociates into dimers. This dissociation seems to be required for the efficient interaction with unfolding proteins that results in the formation of large, regular complexes comprising Hsp26 and the non-native proteins. To gain insight into the molecular mechanism of this chaperone, we analyzed the dynamics and stability of the two oligomeric forms of Hsp 26 (i.e. the 24-mer and the dimer) in comparison to a construct lacking the N-terminal domain (Hsp26⌬N). Furthermore, we determined the stabilities of complexes between Hsp26 and non-native proteins. We show that the temperature-induced dissociation of Hsp26 into dimers is a completely reversible process that involves only a small change in energy. The unfolding of the dissociated Hsp26 dimer or Hsp26⌬N, which is a dimer, requires a much higher energy. Because Hsp26⌬N was inactive as a chaperone, these results imply that the N-terminal domain is of critical importance for both the association of Hsp26 with non-native proteins and the formation of large oligomeric complexes. Interestingly, complexes of Hsp26 with non-native proteins are significantly stabilized against dissociation compared with Hsp26 complexes. Taken together, our findings suggest that the quaternary structure of Hsp26 is determined by two elements, (i) weak, regulatory interactions required to form the shell of 24 subunits and (ii) a strong and stable dimerization of the C-terminal domain.

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Section: Stability Of Hsp26⅐substratementioning

confidence: 99%

mentioning

confidence: 99%

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Analysis of the Regulation of the Molecular Chaperone Hsp26 by Temperature-induced Dissociation

Stromer¹,

Fischer

Richter

et al. 2004

Journal of Biological Chemistry

122

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“…Small heat shock proteins represent a large family of structurally diverse chaperones that form large dynamic oligomers, which bind partially unfolded regions of proteins and prevent their aggregation (1,2). They are found in all biological kingdoms and appear to have evolved early in evolution.…”

mentioning

confidence: 99%

Chaperone Activity of Small Heat Shock Proteins Underlies Therapeutic Efficacy in Experimental Autoimmune Encephalomyelitis

Kurnellas

Brownell

et al. 2012

Journal of Biological Chemistry

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Background:The small heat shock protein, HspB5, is therapeutic in experimental autoimmune encephalomyelitis. Results: Eight other human sHsps, a mycobacterial sHsp, and a linear peptide from HspB5 were equally effective therapeutics. Conclusion: All of the therapeutic proteins and peptides were also molecular chaperones. Significance: Correlation between chaperone activity and therapeutic function supports data demonstrating sHsps bind inflammatory mediators in plasma.

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“…In general, eubacteria and eukaryotes possess all classes of molecular chaperones. For archaeal organisms it could be shown so far that all of them contain genes coding for sHsps [3] and the chaperonin system (Hsp60; thermosome) [4,5]. However, a Hsp90-or a ClpBorthologous protein could not be identified [6].…”

Section: Introductionmentioning

confidence: 99%

Functional characterization of the DnaK chaperone system from the archaeon Methanothermobacter thermautotrophicusΔH

Popp

Reinstein

2009

FEBS Letters

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a b s t r a c tWe characterized the biochemical and functional properties of the DnaK system from the archaeon Methanothermobacter thermautotrophicus DH. In contrast to the eubacterial chaperone components the archaeal Hsp70 system shows thermal transitions only slightly above the optimal environmental temperature (65°C). Nevertheless, it prevents aggregation of luciferase in the physiological temperature range of the organism, but is also fully functional at 30°C in luciferase refolding. Additionally, GrpE M.th. and DnaJ M.th. substitute their eubacterial counterparts whereas DnaK M.th. is only functional with its native cochaperones which could be attributed to a functional specialization of the eubacterial chaperones during evolution.

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Evolution and Diversity of Prokaryotic Small Heat Shock Proteins

Cited by 86 publications

References 29 publications

Analysis of the Regulation of the Molecular Chaperone Hsp26 by Temperature-induced Dissociation

Analysis of the Regulation of the Molecular Chaperone Hsp26 by Temperature-induced Dissociation

Chaperone Activity of Small Heat Shock Proteins Underlies Therapeutic Efficacy in Experimental Autoimmune Encephalomyelitis

Functional characterization of the DnaK chaperone system from the archaeon Methanothermobacter thermautotrophicusΔH

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