Detection and Architecture of Small Heat Shock Protein Monomers

Poulain, Pierre; Gelly, Jean‐Christophe; Flatters, Delphine

doi:10.1371/journal.pone.0009990

Cited by 79 publications

(86 citation statements)

References 55 publications

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“…This observation is in total agreement with the interaction regions of sHSPs with their ATP-dependent chaperone partners such as Hsp70 (Poulain et al, 2010). Additionally, although the S1R functions mainly as an intracellular chaperone protein, an extracellular presence of the S1R secreted from NG108 neuroblastoma glioma hybrid cells has been reported although a chaperoning target has not been unequivocally identified.…”

Section: Biochemical Pharmacology Of the Sigma-1 Receptorsupporting

confidence: 74%

“…Based on current knowledge in the field, the S1R does not bind ATP, in contrast to many large mammalian chaperone-like heat shock proteins such as GRP78/BiP Hsp 70, and Hsp 90 (Hayashi and Su, 2007). Families of small heat shock proteins (sHSPs) consisting of monomer sizes ranging from 12 to 42 kDa that do not bind ATP have been identified in prokaryotes, plants, and mammals (reviewed in Carver et al, 2003;Poulain et al, 2010;Basha et al, 2012). Humans have 10 paralogous sHSPs, HspB1 to HspB10 (Basha et al, 2012).…”

Section: Biochemical Pharmacology Of the Sigma-1 Receptormentioning

confidence: 99%

“…The sHSPs are further defined by a C-terminal domain of approximately 90-100 amino acids known as the alpha crystallins domain that contains seven or eight antiparallel beta strands (for a review, see Basha et al, 2012) and a L/V/I X L/V/I sequence near the C terminus that is important for stabilizing dimer formation (Poulain et al, 2010). A striking Fig.…”

Section: Biochemical Pharmacology Of the Sigma-1 Receptormentioning

confidence: 99%

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Biochemical Pharmacology of the Sigma-1 Receptor

2015

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The sigma-1 receptor (S1R) is a 223 amino acid two transmembrane (TM) pass protein. It is a non-ATP-binding nonglycosylated ligand-regulated molecular chaperone of unknown three-dimensional structure. The S1R is resident to eukaryotic mitochondrial-associated endoplasmic reticulum and plasma membranes with broad functions that regulate cellular calcium homeostasis and reduce oxidative stress. Several multitasking functions of the S1R are underwritten by chaperone-mediated direct (and indirect) interactions with ion channels, G-protein coupled receptors and cell-signaling molecules involved in the regulation of cell growth. The S1R is a promising drug target for the treatment of several neurodegenerative diseases related to cellular stress. In vitro and in vivo functional and molecular characteristics of the S1R and its interactions with endogenous and synthetic small molecules have been discovered by the use of pharmacologic, biochemical, biophysical, and molecular biology approaches. The S1R exists in monomer, dimer, tetramer, hexamer/octamer, and higher oligomeric forms that may be important determinants in defining the pharmacology and mechanism(s) of action of the S1R. A canonical GXXXG in putative TM2 is important for S1R oligomerization. The ligand-binding regions of S1R have been identified and include portions of TM2 and the TM proximal regions of the C terminus. Some client protein chaperone functions and interactions with the cochaperone 78-kDa glucose-regulated protein (binding immunoglobulin protein) involve the C terminus. Based on its biochemical features and mechanisms of chaperone action the possibility that the S1R is a member of the small heat shock protein family is discussed.

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Section: Biochemical Pharmacology Of the Sigma-1 Receptorsupporting

confidence: 74%

Section: Biochemical Pharmacology Of the Sigma-1 Receptormentioning

confidence: 99%

Section: Biochemical Pharmacology Of the Sigma-1 Receptormentioning

confidence: 99%

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Biochemical Pharmacology of the Sigma-1 Receptor

2015

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“…Two such domains form the dimeric building blocks of higher-order oligomers. Dimer formation is mediated by either β-strandexchange of a strand called β6 (in plant, yeast, and bacteria sHsps), or by the interaction of two extended β-strands called β6 + 7 (in metazoan sHsps) (Basha et al 2011;Poulain et al 2010). The α-crystallin domain is flanked by the N-terminal region and the C-terminal extension, both of which are important for oligomer formation.…”

Section: Introductionmentioning

confidence: 99%

Probing the transient interaction between the small heat-shock protein Hsp21 and a model substrate protein using crosslinking mass spectrometry

Lambert

Rutsdottir

Hussein

et al. 2013

Cell Stress and Chaperones

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Small heat-shock protein chaperones are important players in the protein quality control system of the cell, because they can immediately respond to partially unfolded proteins, thereby protecting the cell from harmful aggregates. The small heat-shock proteins can form large polydisperse oligomers that are exceptionally dynamic, which is implicated in their function of protecting substrate proteins from aggregation. Yet the mechanism of substrate recognition remains poorly understood, and little is known about what parts of the small heat-shock proteins interact with substrates and what parts of a partially unfolded substrate protein interact with the small heat-shock proteins. The transient nature of the interactions that prevent substrate aggregation rationalize probing this interaction by crosslinking mass spectrometry. Here, we used a workflow with lysine-specific crosslinking and offline nano-liquid chromatography matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry to explore the interaction between the plant small heat-shock protein Hsp21 and a thermosensitive model substrate protein, malate dehydrogenase. The identified crosslinks point at an interaction between the disordered N-terminal region of Hsp21 and the C-terminal presumably unfolding part of the substrate protein.

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“…As a member of the small molecular weight heat shock protein family, HSPB5 contains a well conserved central "␣-crystallin" domain (ACD), 4 flanked by N-and C-terminal regions (5). The ACDs dimerize and assemble to form a polydisperse ensemble of oligomers, largely through dynamic interactions mediated by the terminal regions (6).…”

mentioning

confidence: 99%

The Human 343delT HSPB5 Chaperone Associated with Early-onset Skeletal Myopathy Causes Defects in Protein Solubility

Mitzelfelt

Limphong

Choi

et al. 2016

Journal of Biological Chemistry

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Mutations of HSPB5 (also known as CRYAB or ␣B-crystallin), a bona fide heat shock protein and molecular chaperone encoded by the HSPB5 (crystallin, alpha B) gene, are linked to multisystem disorders featuring variable combinations of cataracts, cardiomyopathy, and skeletal myopathy. This study aimed to investigate the pathological mechanisms involved in an earlyonset myofibrillar myopathy manifesting in a child harboring a homozygous recessive mutation in HSPB5, 343delT. To study HSPB5 343delT protein dynamics, we utilize model cell culture systems including induced pluripotent stem cells derived from the 343delT patient (343delT/343delT) along with isogenic, heterozygous, gene-corrected control cells (WT KI/ 343delT) and BHK21 cells, a cell line lacking endogenous HSPB5 expression. 343delT/343delT and WT KI/343delT-induced pluripotent stem cell-derived skeletal myotubes and cardiomyocytes did not express detectable levels of 343delT protein, contributable to the extreme insolubility of the mutant protein. Overexpression of HSPB5 343delT resulted in insoluble mutant protein aggregates and induction of a cellular stress response. Co-expression of 343delT with WT prevented visible aggregation of 343delT and improved its solubility. Additionally, in vitro refolding of 343delT in the presence of WT rescued its solubility. We demonstrate an interaction between WT and 343delT both in vitro and within cells. These data support a loss-of-function model for the myopathy observed in the patient because the insoluble mutant would be unavailable to perform normal functions of HSPB5, although additional gain-of-function effects of the mutant protein cannot be excluded. Additionally, our data highlight the solubilization of 343delT by WT, concordant with the recessive inheritance of the disease and absence of symptoms in carrier individuals.HSPB5 (also known as CRYAB or ␣B-crystallin) is a small molecular weight heat shock protein encoded by the HSPB5 (crystallin, alpha B) gene and functions as a molecular chaperone. Its promoter contains a heat shock element, a stress-responsive binding site of heat shock transcription factor 1 (HSF1), that functionally up-regulates the expression of HSPB5. Increased levels of HSPB5 can then go on to provide

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Detection and Architecture of Small Heat Shock Protein Monomers

Cited by 79 publications

References 55 publications

Biochemical Pharmacology of the Sigma-1 Receptor

Biochemical Pharmacology of the Sigma-1 Receptor

Probing the transient interaction between the small heat-shock protein Hsp21 and a model substrate protein using crosslinking mass spectrometry

The Human 343delT HSPB5 Chaperone Associated with Early-onset Skeletal Myopathy Causes Defects in Protein Solubility

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