α‐Crystallin Modulates its Chaperone Activity by Varying the Exposed Surface

Palmieri, Valentina; Maulucci, Giuseppe; Maiorana, Alessandro; Papi, Massimiliano; Spirito, Marco De

doi:10.1002/cbic.201300447

Cited by 12 publications

(15 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The temperature‐dependence of T1107–protein association suggested that its activity could be triggered or modulated by external stimulus. Certain protein chaperones have been reported to have stimuli‐responsive behavior, and some synthetic chaperones have been designed around the concept . T1107 could be directed to “catch‐and‐release” denatured proteins by cycling the temperature.…”

Section: Discussionmentioning

confidence: 99%

The Pentablock Amphiphilic Copolymer T1107 Prevents Aggregation of Denatured and Reduced Lysozyme

et al. 2016

View full text Add to dashboard Cite

Aggregation of denatured or unfolded proteins establishes a large energy barrier to spontaneous recovery of protein form and function following traumatic injury, tissue cryopreservation, and biopharmaceutical storage. Some tissues utilize small heat shock proteins (sHSP) to prevent irreversible aggregation, which allows more complex processes to refold or remove the unfolded proteins. We postulated that large, amphiphilic, and biocompatible block copolymers could mimic sHSP function. Reduced and denatured hen egg white lysozyme (HEWL) was used as a model aggregating protein. The poloxamine T1107 prevented aggregation of HEWL at 37 °C by three complimentary measures. Structural analysis of denatured HEWL revealed a partially-folded conformation with preserved or promoted beta-sheet structures only in the presence of T1107. The physical association of T1107 with denatured HEWL, and the ability to prevent aggregation, was linked to the critical micelle temperature of the polymer. The results suggest that T1107, or a similar amphiphilic block copolymer, could find use as a synthetic chaperone to augment the innate molecular repair mechanisms of natural cells.

show abstract

Section: Discussionmentioning

confidence: 99%

The Pentablock Amphiphilic Copolymer T1107 Prevents Aggregation of Denatured and Reduced Lysozyme

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Oligomerization and chaperone activity depend on all three sHsp domains (Hilario et al 2011 ;Jehle et al 2011 ;Basha et al 2012 ;McDonald et al 2012 ;Hanazono et al 2012 ;Peschek et al 2013 ;Quinlan et al 2013 ), while the amino-and carboxyl-terminal domains, the latter encompassing the IXI motif, also contribute to quaternary dynamics and protein solubility (Basha et al 2012 ;McDonald et al 2012 ;Peschek et al 2013 ;Hilton et al 2013 ;Quinlan et al 2013 ). sHsps are thought to interact with the exposed hydrophobic regions of partially denatured proteins, an activity promoted by changes in oligomer structure that depend upon stress exposure and phosphorylation, and entailing either disassembly of oligomers and/or increases in hydrophobicity by structural rearrangement (Hilario et al 2011 ;McDonald et al 2012 ;Palmieri et al 2013 ;Peschek et al 2013 ) (Fig. 24.1 ).…”

Section: Shsps Are Oligomeric Atp-independent Molecular Chaperonesmentioning

confidence: 99%

Small Heat Shock Proteins and Diapause in the Crustacean, Artemia franciscana

MacRae

2015

Heat Shock Proteins

View full text Add to dashboard Cite

Diapause is a physiological state of metabolic depression and increased stress tolerance observed in many organisms, and especially prominent in insects. The small heat shock proteins (sHsps) mediate protein storage as well as stress tolerance and their accumulation within cells is controlled during diapause. Partially denatured proteins are bound by sHsps preventing their irreversible denaturation, and these proteins are released to Hsp70 and other molecular chaperones for either ATP-dependent folding or degradation. During diapause, which is characterized by exposure to varying levels of stress, proteins are sequestered by sHsps, thus, by enhancing sHsp synthesis the protection of other proteins is maximized. In the crustacean, Artemia franciscana , diapause occurs in encysted gastrula stage embryos (cysts), entailing a profound reduction in metabolism and extreme stress tolerance. Three sHsps, namely p26, ArHsp21 and ArHsp22, accumulate to varying levels in diapause-destined A. franciscana embryos. Experiments performed in vivo by the use of RNA interference (RNAi) demonstrate that p26 has an important role in stress tolerance while also infl uencing embryo development and diapause maintenance. The activities of ArHsp21 and ArHsp22 are less well defi ned although the former sHsp may have a minor role in stress tolerance. The data described herein reveal that the activities of sHsps during diapause are more diverse than previously thought and they contribute to the general understanding of sHsp function.

show abstract

“…Oligomerization and chaperone activity depend on all three sHsp domains , while the amino-and carboxyl-terminal domains, the latter encompassing the IXI motif, also contribute to quaternary dynamics and protein solubility . sHsps are thought to interact with the exposed hydrophobic regions of partially denatured proteins, an activity promoted by changes in oligomer structure that depend upon stress exposure and phosphorylation, and entailing either disassembly of oligomers and/or increases in hydrophobicity by structural rearrangement Palmieri et al 2013 ; ) (Fig. 24.1 ).…”

Section: Other Tauopathiesmentioning

confidence: 99%

The Big Book on Small Heat Shock Proteins

Hightower¹,

Tanguay²

2015

Heat Shock Proteins

View full text Add to dashboard Cite

Heat Shock Proteins: key mediators of Health and Disease. Heat shock proteins (HSP) are essential molecules conserved through cellular evolution required for cells to survive the stresses encountered in the environment and in the tissues of the developing and aging organism. These proteins play the essential roles in stress of preventing the initiation of programmed cell death and repairing damage to the proteome permitting resumption of normal metabolism. Loss of the HSP is lethal either in the short-term in cases of acute stress or in the long-term when exposure to stress is chronic. Cells appear to walk a fi ne line in terms of HSP expression. If expression falls below a certain level, cells become sensitive to oxidative damage that infl uences aging and protein aggregation disease. If HSP levels rise above the normal range, infl ammatory and oncogenic changes occur. It is becoming clear that HSP are emerging as remarkably versatile mediators of health and disease. The aim of this series of volumes is to examine how HSP regulation and expression become altered in pathological states and how this may be remedied by pharmacological and other interventions.More information about this series at

show abstract

α‐Crystallin Modulates its Chaperone Activity by Varying the Exposed Surface

Cited by 12 publications

References 49 publications

The Pentablock Amphiphilic Copolymer T1107 Prevents Aggregation of Denatured and Reduced Lysozyme

The Pentablock Amphiphilic Copolymer T1107 Prevents Aggregation of Denatured and Reduced Lysozyme

Small Heat Shock Proteins and Diapause in the Crustacean, Artemia franciscana

The Big Book on Small Heat Shock Proteins

Contact Info

Product

Resources

About