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Nikolaos Charmpilas, Emmanouil Kyriakakis, Nektarios Tavernarakis
Small heat shock proteins (sHSPs) are gatekeepers of cellular homeostasis across species, preserving proteome integrity under stressful conditions. Nonetheless, recent evidence suggests that sHSPs are more than molecular chaperones with merely auxiliary role. In contrast, sHSPs have emerged as central lifespan determinants, and their malfunction has been associated with the manifestation of neurological disorders, cardiovascular disease and cancer malignancies. In this review, we focus on the role of sHSPs in ageing and age-associated diseases and highlight the most prominent paradigms, where impairment of sHSP function has been implicated in human pathology...
January 10, 2017: Cell Stress & Chaperones
Yael Bar-Lavan, Netta Shemesh, Shiran Dror, Rivka Ofir, Esti Yeger-Lotem, Anat Ben-Zvi
Safeguarding the proteome is central to the health of the cell. In multi-cellular organisms, the composition of the proteome, and by extension, protein-folding requirements, varies between cells. In agreement, chaperone network composition differs between tissues. Here, we ask how chaperone expression is regulated in a cell type-specific manner and whether cellular differentiation affects chaperone expression. Our bioinformatics analyses show that the myogenic transcription factor HLH-1 (MyoD) can bind to the promoters of chaperone genes expressed or required for the folding of muscle proteins...
December 2016: PLoS Genetics
Ahmad F Ahmeda, Mark G Rae, Mohammed F Al Otaibi, Lamyia M Anweigi, Edward J Johns
Vasoconstriction within the renal medulla contributes to the development of hypertension. This study investigated the role of reactive oxygen species (ROS) in regulating renal medullary and cortical blood perfusion (MBP and CBP respectively) in both stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar rats. CBP and MBP were measured using a laser-Doppler flow meter before and after intra-renal infusion of tempol, the superoxide dismutase (SOD) mimetic or tempol plus catalase, the hydrogen peroxide-degrading enzyme...
December 9, 2016: Journal of Physiology and Biochemistry
Evgeny V Mymrikov, Marina Daake, Bettina Richter, Martin Haslbeck, Johannes Buchner
Small heat shock proteins (sHsps) are a ubiquitous family of molecular chaperones that suppress the unspecific aggregation of miscellaneous proteins. Multicellular organisms contain a large number of different sHsps, raising questions as to whether they function redundantly or are specialized in terms of substrates and mechanism. To gain insight into this issue, we undertook a comparative analysis of the 8 major human sHsps on the aggregation of both model proteins and cytosolic lysates under standardized conditions...
November 30, 2016: Journal of Biological Chemistry
Sophia Ungelenk, Fatemeh Moayed, Chi-Ting Ho, Tomas Grousl, Annette Scharf, Alireza Mashaghi, Sander Tans, Matthias P Mayer, Axel Mogk, Bernd Bukau
Small heat shock proteins (sHsp) constitute an evolutionary conserved yet diverse family of chaperones acting as first line of defence against proteotoxic stress. sHsps coaggregate with misfolded proteins but the molecular basis and functional implications of these interactions, as well as potential sHsp specific differences, are poorly explored. In a comparative analysis of the two yeast sHsps, Hsp26 and Hsp42, we show in vitro that model substrates retain near-native state and are kept physically separated when complexed with either sHsp, while being completely unfolded when aggregated without sHsps...
November 30, 2016: Nature Communications
Raquel Martín-Folgar, José-Luis Martínez-Guitarte
Cadmium (Cd) is a widespread and highly toxic heavy metal of particular ecotoxicological relevance for aquatic ecosystems. It occurs naturally in the environment but is also an industrial pollutant with extensively researched carcinogenic potentials. Heat shock proteins (HSPs) are chaperones that play an important role in maintaining protein homeostasis under stress conditions. Small heat shock proteins (sHSPs) comprise the most diverse group of the HSPs family. They are expressed both constitutively and by stress-induction...
February 2017: Chemosphere
F Bozkaya, M O Atli, A Guzeloglu, S A Kayis, M E Yildirim, E Kurar, R Yilmaz, N Aydilek
The aim was to investigate the effects of long-term heat stress and dietary restriction on the expression of certain genes involving in steroidogenic pathway and small heat-shock proteins (sHSPs) in rat testis. Sprague Dawley rats (n = 24) were equally divided into four groups. Group I and II were kept at an ambient temperature of 22°C, while Groups III and IV were reared at 38°C for 9 weeks. Feed was freely available for Group I and Group III, while Group II and Group IV were fed 60% of the diet consumed by their ad libitum counterparts...
September 23, 2016: Andrologia
John J Heikkila
Small heat shock proteins (sHSPs) are a superfamily of molecular chaperones with important roles in protein homeostasis and other cellular functions. Amphibians, reptiles, fish and birds have a shsp gene called hsp30, which was also referred to as hspb11 or hsp25 in some fish and bird species. Hsp30 genes, which are not found in mammals, are transcribed in response to heat shock or other stresses by means of the heat shock factor that is activated in response to an accumulation of unfolded protein. Amino acid sequence analysis revealed that representative HSP30s from different classes of non-mammalian vertebrates were distinct from other sHSPs including HSPB1/HSP27...
January 2017: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
Maxime Bourrelle-Langlois, Geneviève Morrow, Stéphanie Finet, Robert M Tanguay
We previously reported the in silico characterization of Synechococcus sp. phage 18 kDa small heat shock protein (HspSP-ShM2). This small heat shock protein (sHSP) contains a highly conserved core alpha crystalline domain of 92 amino acids and relatively short N- and C-terminal arms, the later containing the classical C-terminal anchoring module motif (L-X-I/L/V). Here we establish the oligomeric profile of HspSP-ShM2 and its structural dynamics under in vitro experimental conditions using size exclusion chromatography (SEC/FPLC), gradient native gels electrophoresis and dynamic light scattering (DLS)...
2016: PloS One
Michela Ciano, Simona Allocca, Maria Camilla Ciardulli, Lucrezia Della Volpe, Stefano Bonatti, Massimo D'Agostino
We have previously shown that αB-crystallin (CRYAB), a small heat shock protein (sHsp) that prevents irreversible aggregation of unfolded protein by an ATP-independent chaperone activity, plays a pivotal role in the biogenesis of multipass transmembrane proteins (TMPs) assisting their folding from the cytosolic side of the endoplasmic reticulum (ER) (D'Agostino et al., 2013). Here we present evidence, based on phosphomimetic substitutions, that the three phosphorytable serine residues at position 19, 45 and 59 of CRYAB play a different regulatory role in this novel chaperone activity: S19 and S45 have a strong inhibitory effect, either alone or in combination, while S59 has not and counteracts the inhibition caused by single phosphomimetic substitutions at S19 and S45...
October 14, 2016: Biochemical and Biophysical Research Communications
Yan Zhang, Baohong Zou, Shan Lu, Yuan Ding, He Liu, Jian Hua
Small heat shock proteins (sHSPs) are molecular chaperones important for stress tolerance. In this study, heat induction of a rice sHSP gene OsHSP16.9C is analyzed to understand the molecular mechanisms underlying gene expression regulation in heat shock responses in rice. Promoter deletion analysis of the OsHSP16.9C using the luciferase (LUC) reporter gene in transgenic rice identifies a critical role of a promoter fragment containing an imperfect heat shock element (HSE) in heat induction. HSE was shown to be important for heat induction of AtHSP18...
October 14, 2016: Biochemical and Biophysical Research Communications
Michael J Poellmann, Tobin R Sosnick, Stephen C Meredith, Raphael C Lee
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 (sHSPs) to prevent irreversible aggregation, which allows more complex processes to refold or remove the unfolded proteins. It is postulated that large, amphiphilic, and biocompatible block copolymers can mimic sHSP function. Reduced and denatured hen egg white lysozyme (HEWL) is used as a model aggregating protein...
September 12, 2016: Macromolecular Bioscience
Dezerae Cox, Emily Selig, Michael D W Griffin, John A Carver, Heath Ecroyd
The aggregation of α-synuclein (α-syn) into amyloid fibrils is associated with neurodegenerative diseases, collectively referred to as the α-synucleinopathies. In vivo, molecular chaperones, such as the small heat-shock proteins (sHsps), normally act to prevent protein aggregation; however, it remains to be determined how aggregation-prone α-syn evades sHsp chaperone action leading to its disease-associated deposition. This work examines the molecular mechanism by which two canonical sHsps, αB-crystallin (αB-c) and Hsp27, interact with aggregation-prone α-syn to prevent its aggregation in vitro Both sHsps are very effective inhibitors of α-syn aggregation, but no stable complex between the sHsps and α-syn was detected, indicating that the sHsps inhibit α-syn aggregation via transient interactions...
October 21, 2016: Journal of Biological Chemistry
Flavia J Krsticevic, Débora P Arce, Joaquín Ezpeleta, Elizabeth Tapia
In plants, fruit maturation and oxidative stress can induce small heat shock protein (sHSP) synthesis to maintain cellular homeostasis. Although the tomato reference genome was published in 2012, the actual number and functionality of sHSP genes remain unknown. Using a transcriptomic (RNA-seq) and evolutionary genomic approach, putative sHSP genes in the Solanum lycopersicum (cv. Heinz 1706) genome were investigated. A sHSP gene family of 33 members was established. Remarkably, roughly half of the members of this family can be explained by nine independent tandem duplication events that determined, evolutionarily, their functional fates...
October 13, 2016: G3: Genes—Genomes—Genetics
Martín D Ré, Carla Gonzalez, Mariela R Escobar, María Laura Sossi, Estela M Valle, Silvana B Boggio
Plants have the largest number of small heat shock proteins (sHsps) (15-42 kDa) among eukaryotes, but little is known about their function in vivo. They accumulate in response to different stresses, and specific sHsps are also expressed during developmental processes such as seed development, germination, and ripening. The presence of organelle-specific sHsps appears to be unique to plants. The sHsps expression is regulated by heat stress transcription factors (Hsfs). In this work, it was explored the role of sHsps in the chilling injury of tomato fruit...
August 22, 2016: Physiologia Plantarum
Eamonn F Healy, Luis Cervantes
Superoxide dismutase [Cu-Zn], or SOD1, is a homo-dimeric protein that functions as an antioxidant by scavenging for superoxides. A wide range of SOD1 variants are linked to inherited, or familial, amyotrophic lateral sclerosis, a progressive and fatal neurodegenerative disease. Aberrant SOD1 oligomerization has been strongly implicated in disease causation, even for sporadic ALS, or SALS, which accounts for ~90 % of ALS cases. Small heat shock proteins (sHSP) have been shown to protect against amyloid fibril formation in vitro, and the sHSP αB-crystallin suppresses in vitro aggregation of SOD1...
December 2016: European Biophysics Journal: EBJ
C Fu, X X Liu, W W Yang, C M Zhao, J Liu
The accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and activates the unfolded protein response (UPR) signaling pathway. The UPR signaling pathway is associated with plant responses to adverse environmental conditions. Thus, changes in the UPR signaling pathway might affect plant abiotic tolerance. Here, the role of ER small heat-shock protein (ER-sHSP) in improving plant resistance to salt stress was explored. Under salt stress conditions, ER-sHSP transgenic plants were found to have more vigorous roots, maintain a higher relative water content, absorb less Na(+), accumulate more osmolytes and Ca(2+), and sustain less damage to the photosystem, compared to wild-type non-transgenic plants...
July 14, 2016: Genetics and Molecular Research: GMR
Stéphanie Weidmann, Magali Maitre, Julie Laurent, Françoise Coucheney, Aurélie Rieu, Jean Guzzo
Lactococcus lactis is a lactic acid bacterium widely used in cheese and fermented milk production. During fermentation, L. lactis is subjected to acid stress that impairs its growth. The small heat shock protein (sHsp) Lo18 from the acidophilic species Oenococcus oeni was expressed in L. lactis. This sHsp is known to play an important role in protein protection and membrane stabilization in O. oeni. The role of this sHsp could be studied in L. lactis, since no gene encoding for sHsp has been detected in this species...
June 8, 2016: International Journal of Food Microbiology
Emmanuel Jaspard, Gilles Hunault
BACKGROUND: small Heat Shock Proteins (sHSP) is a wide proteins family. SHSP are found in all kingdoms and they play critical roles in plant stress tolerance mechanisms (as well as in pathogenic microorganisms and are implicated in human diseases). RESULTS: sHSPdb (small Heat Shock Proteins database) is an integrated resource containing non-redundant, full-length and curated sequences of sHSP, classified on the basis of amino acids motifs and physico-chemical properties...
2016: BMC Plant Biology
Svetlana G Roman, Natalia A Chebotareva, Boris I Kurganov
It's becoming evident that small heat shock proteins (sHsps) are important players of protein homeostasis system. Their ability to bind misfolded proteins may play a crucial role in preventing protein aggregation in cells. The remarkable structural plasticity of sHsps is considered to underlie the mechanism of their activity. However, all our knowledge of the anti-aggregation functioning of sHsps is based on data obtained in vitro in media greatly different from the cellular highly crowded milieu. The present review highlights available data on the effect of crowding on the anti-aggregation activity of sHsps...
May 24, 2016: International Journal of Biological Macromolecules
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