Cytoskeletal disruption and small heat shock protein translocation immediately after lengthening contractions

2004 ◽  
Vol 286 (3) ◽  
pp. C713-C722 ◽  
Author(s):  
Timothy J. Koh ◽  
Joel Escobedo
Keyword(s):  
Heat Shock ◽  
Protein Translocation ◽  
Small Heat Shock Protein ◽  
Insoluble Fraction ◽  
Scaffolding Proteins ◽  
Lengthening Contractions ◽  
Small Hsps ◽  
Αb Crystallin ◽  
Shock Proteins ◽  
Cytoskeletal Elements

The purposes of this study were to determine whether, immediately after lengthening contractions, 1) levels of specific force-transmitting cytoskeletal elements are reduced in skeletal muscle cells and 2) cytosolic small heat shock proteins (HSPs) translocate to structures prone to disruption. Western blot analysis demonstrated decreased concentrations of z-disk proteins α-actinin and plectin and membrane scaffolding proteins dystrophin and β-spectrin in muscle exposed to lengthening contractions compared with contralateral control muscle. Lengthening contractions also resulted in immediate translocation of constitutively expressed HSP25 and αB-crystallin from the soluble to the insoluble fraction of muscle homogenates, and cryosections showed translocation from a diffuse, cytosolic localization to striations that corresponded to z-disks. Lengthening contraction-induced translocation of HSP25 and αB-crystallin was associated with phosphorylation of these small HSPs, which may trigger their protective activity. In summary, these findings demonstrate loss of z-disk and membrane scaffolding proteins immediately after lengthening contractions, and concomitant translocation of HSP25 and αB-crystallin to the z-disk, which may help to stabilize or repair cytoskeletal elements at this site.

scholarly journals Single-molecule fluorescence-based approach reveals novel mechanistic insights into human small heat shock protein chaperone function

2020 ◽  
pp. jbc.RA120.015419
Author(s):  
Caitlin L Johnston ◽  
Nicholas R Marzano ◽  
Bishnu P Paudel ◽  
George Wright ◽  
Justin L.P. Benesch ◽  
...  
Keyword(s):  
Heat Shock ◽  
Single Molecule ◽  
Small Heat Shock Protein ◽  
Vital Role ◽  
Misfolded Proteins ◽  
Single Molecule Fluorescence ◽  
Chaperone Function ◽  
Αb Crystallin ◽  
Client Proteins ◽  
Shock Proteins

Small heat shock proteins (sHsps) are a family of ubiquitous intracellular molecular chaperones that are up-regulated under stress conditions and play a vital role in protein homeostasis (proteostasis). It is commonly accepted that these chaperones work by trapping misfolded proteins to prevent their aggregation; however, fundamental questions regarding the molecular mechanism by which sHsps interact with misfolded proteins remain unanswered. The dynamic and polydisperse nature of sHsp oligomers has made studying them challenging using traditional biochemical approaches. Therefore, we have utilized a single-molecule fluorescence-based approach to observe the chaperone action of human αB-crystallin (αBc, HSPB5). Using this approach we have, for the first time, determined the stoichiometries of complexes formed between αBc and a model client protein, chloride intracellular channel 1 (CLIC1). By examining the dispersity and stoichiometries of these complexes over time, and in response to different concentrations of αBc, we have uncovered unique and important insights into a two-step mechanism by which αBc interacts with misfolded client proteins to prevent their aggregation.

scholarly journals Disruption of the three cytoskeletal networks in mammalian cells does not affect transcription, translation, or protein translocation changes induced by heat shock.

1985 ◽  
Vol 5 (7) ◽  
pp. 1571-1581 ◽  
Author(s):  
W J Welch ◽  
J R Feramisco
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Mammalian Cells ◽  
Stress Proteins ◽  
Protein Translocation ◽  
Shock Response ◽  
Cytochalasin E ◽  
Cytoskeletal Networks ◽  
Shock Proteins ◽  
Cytoskeletal Elements

Mammalian cells show a complex series of transcriptional and translational switching events in response to heat shock treatment which ultimately lead to the production and accumulation of a small number of proteins, the so-called heat shock (or stress) proteins. We investigated the heat shock response in both qualitative and quantitative ways in cells that were pretreated with drugs that specifically disrupt one or more of the three major cytoskeletal networks. (These drugs alone, cytochalasin E and colcemid, do not result in induction of the heat shock response.) Our results indicated that disruption of the actin microfilaments, the vimentin-containing intermediate filaments, or the microtubules in living cells does not hinder the ability of the cell to undergo an apparently normal heat shock response. Even when all three networks were simultaneously disrupted (resulting in a loose, baglike appearance of the cells), the cells still underwent a complete heat shock response as assayed by the appearance of the heat shock proteins. In addition, the major induced 72-kilodalton heat shock protein was efficiently translocated from the cytoplasm into its proper location in the nucleus and nucleolus irrespective of the condition of the three cytoskeletal elements.

scholarly journals The Small Heat Shock Protein HSP25/27 (HspB1) Is Abundant in Cultured Astrocytes and Associated with Astrocytic Pathology in Progressive Supranuclear Palsy and Corticobasal Degeneration

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Lisa Schwarz ◽  
Grit Vollmer ◽  
Christiane Richter-Landsberg
Keyword(s):  
Heat Shock ◽  
Neurodegenerative Disorders ◽  
Corticobasal Degeneration ◽  
Small Heat Shock Protein ◽  
Immunoblot Analysis ◽  
Culture Studies ◽  
Protein Levels ◽  
Cultured Astrocytes ◽  
Small Hsps ◽  
Shock Proteins

Filamentous tau-positive protein inclusions in neurons and glia are prominent features of a number of neurodegenerative disorders termed tauopathies. These inclusions are further characterized by the presence of heat shock proteins (HSPs). The group of small HSPs, namely, HSP27 andαB-crystallin, interact with the cytoskeleton, bind to nonnative proteins, and prevent their aggregation after stress. To further investigate their contribution to neurodegenerative diseases, we have analyzed the association of HSP27 with pathological lesions of tauopathies. Microarray and immunoblot analysis revealed that HSP27 is enhanced at the mRNA and protein levels in affected brains, and that it is associated with astrocytic pathology. The upregulation of HSP27 in tauopathies with gial pathology implies distinct mechanisms for glial and neuronal cells. This was sustained by cell culture studies, demonstrating that the small HSPs are specifically and prominently expressed in unstressed astrocytes and not in neurons and in neurons remained at a rather low level even after stress situations.

Disruption of the three cytoskeletal networks in mammalian cells does not affect transcription, translation, or protein translocation changes induced by heat shock

1985 ◽  
Vol 5 (7) ◽  
pp. 1571-1581
Author(s):  
W J Welch ◽  
J R Feramisco
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Mammalian Cells ◽  
Stress Proteins ◽  
Protein Translocation ◽  
Shock Response ◽  
Cytochalasin E ◽  
Cytoskeletal Networks ◽  
Shock Proteins ◽  
Cytoskeletal Elements

Mammalian cells show a complex series of transcriptional and translational switching events in response to heat shock treatment which ultimately lead to the production and accumulation of a small number of proteins, the so-called heat shock (or stress) proteins. We investigated the heat shock response in both qualitative and quantitative ways in cells that were pretreated with drugs that specifically disrupt one or more of the three major cytoskeletal networks. (These drugs alone, cytochalasin E and colcemid, do not result in induction of the heat shock response.) Our results indicated that disruption of the actin microfilaments, the vimentin-containing intermediate filaments, or the microtubules in living cells does not hinder the ability of the cell to undergo an apparently normal heat shock response. Even when all three networks were simultaneously disrupted (resulting in a loose, baglike appearance of the cells), the cells still underwent a complete heat shock response as assayed by the appearance of the heat shock proteins. In addition, the major induced 72-kilodalton heat shock protein was efficiently translocated from the cytoplasm into its proper location in the nucleus and nucleolus irrespective of the condition of the three cytoskeletal elements.

scholarly journals The Archaeal Small Heat Shock Protein Hsp17.6 Protects Proteins from Oxidative Inactivation

2021 ◽  
Vol 22 (5) ◽  
pp. 2591
Author(s):  
Pengfei Ma ◽  
Jie Li ◽  
Lei Qi ◽  
Xiuzhu Dong
Keyword(s):  
Heat Shock ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Small Heat Shock Protein ◽  
Phase Cell ◽  
Molecular Weights ◽  
Oxidative Inactivation ◽  
Methionine Residues ◽  
Shock Proteins ◽  
And Function

Small heat shock proteins (sHsps) are widely distributed among various types of organisms and function in preventing the irreversible aggregation of thermal denaturing proteins. Here, we report that Hsp17.6 from Methanolobus psychrophilus exhibited protection of proteins from oxidation inactivation. The overexpression of Hsp17.6 in Escherichia coli markedly increased the stationary phase cell density and survivability in HClO and H2O2. Treatments with 0.2 mM HClO or 10 mM H2O2 reduced malate dehydrogenase (MDH) activity to 57% and 77%, whereas the addition of Hsp17.6 recovered the activity to 70–90% and 86–100%, respectively. A similar effect for superoxide dismutase oxidation was determined for Hsp17.6. Non-reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis assays determined that the Hsp17.6 addition decreased H2O2-caused disulfide-linking protein contents and HClO-induced degradation of MDH; meanwhile, Hsp17.6 protein appeared to be oxidized with increased molecular weights. Mass spectrometry identified oxygen atoms introduced into the larger Hsp17.6 molecules, mainly at the aspartate and methionine residues. Substitution of some aspartate residues reduced Hsp17.6 in alleviating H2O2- and HClO-caused MDH inactivation and in enhancing the E. coli survivability in H2O2 and HClO, suggesting that the archaeal Hsp17.6 oxidation protection might depend on an “oxidant sink” effect, i.e., to consume the oxidants in environments via aspartate oxidation

scholarly journals Induction and phosphorylation of the small heat shock proteins HspB1/Hsp25 and HspB5/αB-crystallin in the rat retina upon optic nerve injury

2015 ◽  
Vol 21 (1) ◽  
pp. 167-178 ◽  
Author(s):  
Thomas Schmidt ◽  
Dietmar Fischer ◽  
Anastasia Andreadaki ◽  
Britta Bartelt-Kirbach ◽  
Nikola Golenhofen
Keyword(s):  
Optic Nerve ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Nerve Injury ◽  
Small Heat Shock Proteins ◽  
Optic Nerve Injury ◽  
Rat Retina ◽  
Αb Crystallin ◽  
Shock Proteins

scholarly journals Heat shock factor 2 is required for maintaining proteostasis against febrile-range thermal stress and polyglutamine aggregation

2011 ◽  
Vol 22 (19) ◽  
pp. 3571-3583 ◽  
Author(s):  
Toyohide Shinkawa ◽  
Ke Tan ◽  
Mitsuaki Fujimoto ◽  
Naoki Hayashida ◽  
Kaoru Yamamoto ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Heat Shock ◽  
Protein Misfolding ◽  
Reproductive Organs ◽  
Heat Shock Factors ◽  
Mild Heat ◽  
Promising Therapeutic Target ◽  
Αb Crystallin ◽  
Shock Proteins ◽  
Polyglutamine Protein

Heat shock response is characterized by the induction of heat shock proteins (HSPs), which facilitate protein folding, and non-HSP proteins with diverse functions, including protein degradation, and is regulated by heat shock factors (HSFs). HSF1 is a master regulator of HSP expression during heat shock in mammals, as is HSF3 in avians. HSF2 plays roles in development of the brain and reproductive organs. However, the fundamental roles of HSF2 in vertebrate cells have not been identified. Here we find that vertebrate HSF2 is activated during heat shock in the physiological range. HSF2 deficiency reduces threshold for chicken HSF3 or mouse HSF1 activation, resulting in increased HSP expression during mild heat shock. HSF2-null cells are more sensitive to sustained mild heat shock than wild-type cells, associated with the accumulation of ubiquitylated misfolded proteins. Furthermore, loss of HSF2 function increases the accumulation of aggregated polyglutamine protein and shortens the lifespan of R6/2 Huntington's disease mice, partly through αB-crystallin expression. These results identify HSF2 as a major regulator of proteostasis capacity against febrile-range thermal stress and suggest that HSF2 could be a promising therapeutic target for protein-misfolding diseases.

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