scholarly journals Small heat shock proteins inhibit in vitro Aβ1-42 amyloidogenesis

FEBS Letters ◽  
1997 ◽  
Vol 416 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Yogish C Kudva ◽  
Henry J Hiddinga ◽  
Peter C Butler ◽  
Cheryl S Mueske ◽  
Norman L Eberhardt
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
Shock Proteins

In Vitro Holdase Activity of E. coli Small Heat-Shock Proteins IbpA, IbpB and IbpAB: A Biophysical Study with Some Unconventional Techniques

2014 ◽  
Vol 21 (6) ◽  
pp. 564-571 ◽  
Author(s):  
Sourav Roy ◽  
Monobesh Patra ◽  
Suman Nandy ◽  
Milon Banik ◽  
Rakhi Dasgupta ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
E Coli ◽  
Biophysical Study ◽  
Shock Proteins

Translation of Some Maize Small Heat Shock Proteins Is Initiated From Internal In-Frame AUGs

Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 471-477
Author(s):  
J Roger H Frappier ◽  
David B Walden ◽  
Burr G Atkinson
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Single Gene ◽  
Small Heat Shock Proteins ◽  
Shock Proteins

Abstract Etiolated maize radicles (inbred Oh43) subjected to a brief heat shock synthesize a family of small heat shock proteins (≃18 kD) that is composed of at least 12 members. We previously described the cDNA-derived sequence of three maize shsp mRNAs (cMHSP18-1, cMHSP18-3, and cMHSP18-9). In this report, we demonstrate that the mRNA transcribed in vitro from one of these cDNAs (cMHSP 18-9) is responsible for the synthesis of three members of the shsp family, and we suggest that cMHSP18-3 may be responsible for the synthesis of three additional members and cMHSP18-1 for the synthesis of two other members of this family. The fact that these genes do not contain introns, coupled with the observations reported herein, suggest that maize may have established another method of using a single gene to produce a number of different proteins.

Abstract 226: Human Cardiomyocytes Are Protected From Stress-induced Stiffening By Binding Of Small Heat Shock Proteins To Titin Spring Elements

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Sebastian Kotter ◽  
Andreas Unger ◽  
Nazha Hamdani ◽  
Wolfgang A Linke
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Protective Effect ◽  
Small Heat Shock Proteins ◽  
Stress Conditions ◽  
Passive Stiffness ◽  
Human Cardiomyocytes ◽  
Αb Crystallin ◽  
Shock Proteins

Introduction: Small heat-shock proteins (sHSPs) generally participate in cellular protein quality-control mechanisms. They are abundant in cardiomyocytes where they bind under diverse stress conditions preferentially to myofilament proteins. The functional role of this association is unclear. Hypothesis: HSP27 and αB-crystallin bind to human cardiac titin spring elements and exert a protective effect on cardiomyocyte passive stiffness under stress conditions. Methods: Binding of sHSPs to recombinant human titin constructs was characterized by GST-pulldown assay and confirmed by immunofluorescence staining of human donor and failing (DCM) cardiomyocytes. Sedimentation-velocity centrifugation, photometric and chromatographic methods were used to test for titin aggregation and protection from it by sHSPs. Passive force was measured in isolated human cardiomyocytes or single myofibrils, in search for a possible protective effect of sHSPs on mechanical function. Results: HSP27 interacted with distinct domains of the human titin-spring region in vitro and in cardiomyocytes, and independent of the presence of actin filaments in the sarcomeres. The binding sites on the elastic titin segment resemble those for αB-crystallin and include proximal Ig-domains, the N2-B and N2-A regions, but not the PEVK-domain. In-vitro assays revealed a monomeric organization of these titin-spring elements; however, unfolded N2-A domain (mainly composed of Ig-domains) aggregated in pH-6.6 buffer but not in normal-pH buffer, whereas αB-crystallin protected from this effect. The intrinsically disordered N2-Bus titin domain did not aggregate. Single skinned human cardiomyocytes showed greatly increased passive stiffness when pre-stretched under acidic stress (pH 6.6), but αB-crystallin or HSP27 corrected the stiffening. In failing patient heart tissue, both HSP27 and αB-crystallin frequently associated with the elastic I-band region, in contrast to a cytosolic and Z-disk location of these sHSPs in donor heart. Conclusions: In cardiomyocytes sHSPs bind to mechanically active titin domains under stress conditions such as intracellular acidosis ( e.g. , ischemia), protecting the titin springs from aggregation and helping reverse diastolic stiffening.

scholarly journals The small heat shock proteins αB-crystallin and Hsp27 suppress SOD1 aggregation in vitro

2012 ◽  
Vol 18 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Justin J. Yerbury ◽  
Dane Gower ◽  
Laura Vanags ◽  
Kate Roberts ◽  
Jodi A. Lee ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
Αb Crystallin ◽  
Shock Proteins

scholarly journals Human myocytes are protected from titin aggregation-induced stiffening by small heat shock proteins

2014 ◽  
Vol 204 (2) ◽  
pp. 187-202 ◽  
Author(s):  
Sebastian Kötter ◽  
Andreas Unger ◽  
Nazha Hamdani ◽  
Patrick Lang ◽  
Matthias Vorgerd ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
Pevk Domain ◽  
Functional Implications ◽  
Αb Crystallin ◽  
Acidic Conditions ◽  
Shock Proteins ◽  
Ig Domain

In myocytes, small heat shock proteins (sHSPs) are preferentially translocated under stress to the sarcomeres. The functional implications of this translocation are poorly understood. We show here that HSP27 and αB-crystallin associated with immunoglobulin-like (Ig) domain-containing regions, but not the disordered PEVK domain (titin region rich in proline, glutamate, valine, and lysine), of the titin springs. In sarcomeres, sHSP binding to titin was actin filament independent and promoted by factors that increased titin Ig unfolding, including sarcomere stretch and the expression of stiff titin isoforms. Titin spring elements behaved predominantly as monomers in vitro. However, unfolded Ig segments aggregated, preferentially under acidic conditions, and αB-crystallin prevented this aggregation. Disordered regions did not aggregate. Promoting titin Ig unfolding in cardiomyocytes caused elevated stiffness under acidic stress, but HSP27 or αB-crystallin suppressed this stiffening. In diseased human muscle and heart, both sHSPs associated with the titin springs, in contrast to the cytosolic/Z-disk localization seen in healthy muscle/heart. We conclude that aggregation of unfolded titin Ig domains stiffens myocytes and that sHSPs translocate to these domains to prevent this aggregation.

scholarly journals Contraction in Human Myometrium Is Associated with Changes in Small Heat Shock Proteins

Endocrinology ◽  
2007 ◽  
Vol 149 (1) ◽  
pp. 245-252 ◽  
Author(s):  
David A. MacIntyre ◽  
Elisa K. Tyson ◽  
Mark Read ◽  
Roger Smith ◽  
George Yeo ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
Human Myometrium ◽  
Proteomic Approach ◽  
Hsp27 Phosphorylation ◽  
Αb Crystallin ◽  
Muscle Types ◽  
Shock Proteins

The myometrium undergoes substantial remodeling at the time of labor including rearrangement of the cellular contractile machinery. The regulation of this process in human myometrium at the time of labor is poorly defined, but evidence in other muscle types suggests modulation by small heat shock proteins (sHSP). The aim of this study was to investigate whether similar changes in sHSP occur in the myometrium at labor. Using a quantitative proteomic approach (two-dimensional difference gel electrophoresis), we found a 69% decrease in the sHSP αB-crystallin in the myometrium at labor plus multiple isoforms of HSP27. Immunoblotting using phosphospecific HSP27 antibodies (HSP27-serine15, -78, and -82) detected marked changes in HSP27 phosphorylation at labor. Although total HSP27 levels were unchanged, HSP27-Ser15 was 3-fold higher at labor. Coimmunoprecipitation studies showed that HSP27 coprecipitates with αB-crystallin and also smooth muscle α-actin. Coimmunofluorescence studies demonstrated a relocation of HSP27 from the perinuclear region to the actin cytoskeleton at labor. The functional significance of these changes was demonstrated in vitro where myometrial strips stimulated to contract with oxytocin exhibited increased HSP27-Ser15 phosphorylation. Our findings provide data consistent with a novel pathway regulating human myometrial contraction at labor and identify HSP27 and αB-crystallin as potential targets for future tocolytic design.

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