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Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more stressful conditions. In the context of climate change, stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with stress resistance. However, multistress resistance cannot be obtained from the simple addition of single stress resistance traits. In the field, stresses are unpredictable and several may occur at once. Consequently, the use of single stress resistance traits is often inadequate. Although it has been historically linked with the heat stress response, the heat‐shock protein (HSP)/chaperone network is a major component of multiple stress responses. Among the HSP/chaperone ‘client proteins’, many are primary metabolism enzymes and signal transduction components with essential roles for the proper functioning of a cell. HSPs/chaperones are controlled by the action of diverse heat‐shock factors, which are recruited under stress conditions. In this review, we give an overview of the regulation of the HSP/chaperone network with a focus on Arabidopsis thaliana. We illustrate the role of HSPs/chaperones in regulating diverse signalling pathways and discuss several basic principles that should be considered for engineering multiple stress resistance in crops through the HSP/chaperone network. 相似文献
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The natural life cycle of many protozoan and helminth parasites involves exposure to several hostile environmental conditions. Under these circumstances, the parasites arouse a cellular stress response that involves the expression of heat shock proteins (HSPs). Small HSPs (sHSPs) constitute one of the main families of HSPs. The sHSPs are very divergent at the sequence level, but their secondary and tertiary structures are conserved and some of its members are related to α-crystallin from vertebrates. They are involved in a variety of cellular processes. As other HSPs, the sHSPs act as molecular chaperones; however, they have shown other activities apparently not related to chaperone action. In this review, the diverse activities of sHSPs in the major genera of protozoan and helminth parasites are described. These include stress response, development, and immune response, among others. In addition, an analysis comparing the sequences of sHSPs from some parasites using a distance analysis is presented. Because many parasites face hostile conditions through its life cycles the study of HSPs, including sHSPs, is fundamental. 相似文献
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Nuclear localization and the heat shock proteins 总被引:1,自引:0,他引:1
The highly conserved heat shock proteins (HSP) belong to a subset of cellular proteins that localize to the nucleus. HSPs
are atypical nuclear proteins in that they localize to the nucleus selectively, rather than invariably. Nuclear localization
of HSPs is associated with cell stress and cell growth. This aspect of HSPs is highly conserved with nuclear localization
occurring in response to a wide variety of cell stresses. Nuclear localization is likely important for at least some of the
heat shock proteins’ protective functions; little is known about the function of the heat shock proteins in the nucleus. Nuclear
localization is signalled by the presence of a basic nuclear localization sequence (NLS) within a protein. Though most is
known about HSP 72’s nuclear localization, the NLS(s) has not been definitively identified for any of the heat shock proteins.
Likely more is involved than presence of a NLS; since the heat shock proteins only localize to the nucleus under selective
conditions, nuclear localization must be regulated. HSPs also function as chaperons of nuclear transport, facilitating the
movement of other macromolecules across the nuclear membrane. The mechanisms involved in chaperoning of proteins by HSPs into
the nucleus are still being identified. 相似文献
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Anson Pierce Natalia Podlutskaya Jonathan J. Halloran Stacy A. Hussong Pei‐Yi Lin Raquel Burbank Matthew J. Hart Veronica Galvan 《Journal of neurochemistry》2013,124(6):880-893
Rapamycin, an inhibitor of target‐of‐rapamycin, extends lifespan in mice, possibly by delaying aging. We recently showed that rapamycin halts the progression of Alzheimer's (AD)‐like deficits, reduces amyloid‐beta (Aβ) and induces autophagy in the human amyloid precursor protein (PDAPP) mouse model. To delineate the mechanisms by which chronic rapamycin delays AD we determined proteomic signatures in brains of control‐ and rapamycin‐treated PDAPP mice. Proteins with reported chaperone‐like activity were overrepresented among proteins up‐regulated in rapamycin‐fed PDAPP mice and the master regulator of the heat‐shock response, heat‐shock factor 1, was activated. This was accompanied by the up‐regulation of classical chaperones/heat shock proteins (HSPs) in brains of rapamycin‐fed PDAPP mice. The abundance of most HSP mRNAs except for alpha B‐crystallin, however, was unchanged, and the cap‐dependent translation inhibitor 4E‐BP was active, suggesting that increased expression of HSPs and proteins with chaperone activity may result from preferential translation of pre‐existing mRNAs as a consequence of inhibition of cap‐dependent translation. The effects of rapamycin on the reduction of Aβ, up‐regulation of chaperones, and amelioration of AD‐like cognitive deficits were recapitulated by transgenic over‐expression of heat‐shock factor 1 in PDAPP mice. These results suggest that, in addition to inducing autophagy, rapamycin preserves proteostasis by increasing chaperones. We propose that the failure of proteostasis associated with aging may be a key event enabling AD, and that chronic inhibition of target‐of‐rapamycin may delay AD by maintaining proteostasis in brain. Read the Editorial Highlight for this article on doi: 10.1111/jnc.12098 . 相似文献
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AsHSP17, a creeping bentgrass small heat shock protein modulates plant photosynthesis and ABA‐dependent and independent signalling to attenuate plant response to abiotic stress
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Xinbo Sun Chunyu Sun Zhigang Li Qian Hu Liebao Han Hong Luo 《Plant, cell & environment》2016,39(6):1320-1337
Heat shock proteins (HSPs) are molecular chaperones that accumulate in response to heat and other abiotic stressors. Small HSPs (sHSPs) belong to the most ubiquitous HSP subgroup with molecular weights ranging from 12 to 42 kDa. We have cloned a new sHSP gene, AsHSP17 from creeping bentgrass (Agrostis stolonifera) and studied its role in plant response to environmental stress. AsHSP17 encodes a protein of 17 kDa. Its expression was strongly induced by heat in both leaf and root tissues, and by salt and abscisic acid (ABA) in roots. Transgenic Arabidopsis plants constitutively expressing AsHSP17 exhibited enhanced sensitivity to heat and salt stress accompanied by reduced leaf chlorophyll content and decreased photosynthesis under both normal and stressed conditions compared to wild type. Overexpression of AsHSP17 also led to hypersensitivity to exogenous ABA and salinity during germination and post‐germinative growth. Gene expression analysis indicated that AsHSP17 modulates expression of photosynthesis‐related genes and regulates ABA biosynthesis, metabolism and ABA signalling as well as ABA‐independent stress signalling. Our results suggest that AsHSP17 may function as a protein chaperone to negatively regulate plant responses to adverse environmental stresses through modulating photosynthesis and ABA‐dependent and independent signalling pathways. 相似文献
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Clostridium botulinum type A cells, when challenged to elevated temperature (45°C), increased the expression of at least nine heat shock proteins (HSPs). Simultaneously with the induction of HSPs, changes in the synthesis rates of other cellular proteins were observed. A 40-kDa stress protein was induced and its synthesis rate was enhanced when the cells were shifted to 45°C. Using heterologous antibodies raised against E. coli DnaJ heat shock proteins, the 40-kDa stress protein of C. botulinum type A has been identified as a DnaJ-like chaperone. The DnaJ chaperone might be involved in translocation of the neurotoxin and other cellular proteins across the cell membrane, repair of damaged proteins, and organism survival inside the host. This is the first report of the existence of a DnaJ-like chaperone in this organism. 相似文献
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本文介绍了植物热激蛋白的产:生、分布和分类。着重论述了热激反应的特点、植物热激蛋白的功能、热激基因表达与调控的研究进展。 相似文献
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Wai‐Lok Yau Ulrike Lambertz Lucie Colineau Pascale Pescher Andrea MacDonald Dorothea Zander Silke Retzlaff Julia Eick Neil E. Reiner Joachim Clos Gerald F. Späth 《The Journal of eukaryotic microbiology》2016,63(6):823-833
Protozoan parasites of the genus Leishmania adapt to their arthropod and vertebrate hosts through the development of defined life cycle stages. Stage differentiation is triggered by environmental stress factors and has been linked to parasite chaperone activities. Using a null mutant approach we previously revealed important, nonredundant functions of the cochaperone cyclophilin 40 in L. donovani‐infected macrophages. Here, we characterized in more detail the virulence defect of cyp40?/? null mutants. In vitro viability assays, infection tests using macrophages, and mixed infection experiments ruled out a defect of cyp40?/? parasites in resistance to oxidative and hydrolytic stresses encountered inside the host cell phagolysosome. Investigation of the CyP40‐dependent proteome by quantitative 2D‐DiGE analysis revealed up regulation of various stress proteins in the null mutant, presumably a response to compensate for the lack of CyP40. Applying transmission electron microscopy we showed accumulation of vesicular structures in the flagellar pocket of cyp40?/? parasites that we related to a significant increase in exosome production, a phenomenon previously linked to the parasite stress response. Together these data suggest that cyp40?/? parasites experience important intrinsic homeostatic stress that likely abrogates parasite viability during intracellular infection. 相似文献
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Alexandros Alexandratos Joachim Clos Martina Samiotaki Antonia Efstathiou George Panayotou Ketty Soteriadou Despina Smirlis 《Molecular microbiology》2013,88(5):1015-1031
Overexpression of Leishmania histone H1 (LeishH1) was previously found to cause a promastigote‐to‐amastigote differentiation handicap, deregulation of cell‐cycle progression, and loss of parasite infectivity. The aim of this study was to identify changes in the proteome of LeishH1 overexpressing parasites associated with the avirulent phenotype observed. 2D‐gel electrophoresis analysis revealed only a small protein subset of differentially expressed proteins in the LeishH1 overexpressing promastigotes. Among these was the chaperone HSP83, known for its protective role in Leishmania drug‐induced apoptosis, which displayed lower translational rates. To investigate if the lower expression levels of HSP83 are associated with the differentiation handicap, we assayed the thermostability of parasites by subjecting them to heat‐shock (25°C→37°C), a natural stress‐factor occurring during stage differentiation. Heat‐shock promoted apoptosis to a greater extent in the LeishH1 overexpressing parasites. Interestingly, these parasites were not only more sensitive to heat‐shock but also to drug‐induced [Sb(III)] cell‐death. In addition, the restoration of HSP83 levels re‐established drug resistance, and restored infectivity to LeishH1 overexpressing parasites in the murine J774 macrophage model. Overall, this study suggests that LeishH1 levels are critical for the parasite's stress‐induced adaptation within the mammalian host, and highlights the cross‐talk between pathways involved in drug resistance, apoptosis and virulence. 相似文献
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昆虫的热休克反应和热休克蛋白 总被引:5,自引:1,他引:5
热休克(热激heatshock)是指短暂、迅速地向高温转换所诱导出的一种固定的应激反应。诱导该反应的温度在种与种之间有所不同。热休克反应最明显的特征是:伴随着正常蛋白质合成的抑制,一部分特殊蛋白质的诱导和表达增加,即为热休克蛋白(heatshockproteins,HSPs)。尽管热休克蛋白的合成也能被其它形式的应激反应所诱导,将它们认为是应激蛋白可能更恰当,但人们习惯上仍将这类蛋白质称为热休克蛋白。由于热休克反应和热休克蛋白是在果蝇(Drosophiliamelanogaster)中最初发现的,故在昆虫中,特别是果蝇等双翅目昆虫中研究得较深入… 相似文献