果蝇的热休克反应

热休克反应最早在果蝇中发现,其过程伴随着一系列特殊蛋白--热休克蛋白（HSPs）的增量表达.热休克蛋白包括多个家族,它们在热休克反应中表现出复杂的表达调控机制,并具有组织和发育阶段特异性.研究热休克反应具有重要的生物学意义,在医学、工业等的应用前景十分广阔.     

热休克因子生理功能研究进展

热休克因子是调控真核细胞热休克基因转录的关键因子,在应激和正常生理条件下发挥重要作用,使其成为近年来的研究热点。该文简要综述热休克因子在抗炎反应、肿瘤发生与维持、生长发育、衰老等生理病理过程中的重要生理功能。     

生物的热休克反应研究进展

介绍了生物应激反应的基本概念、基本知识、研究概况、热休克蛋白的作用及与细胞凋亡的关系。     

人热休克因子1突变体的应用研究进展

热休克因子1是调节应激反应的主要转录因子,它在应激条件下可被活化。通过基因突变得到正显性和负显性热休克因子1,它们不需要外界条件刺激就分别具有启动热休克蛋白的表达或竞争抑制内源热休克因子1活性的能力。目前,已有多个热休克因子1的突变体应用于疾病研究。介绍了热休克因子1的结构和活化途径,以及热休克因子1突变体在肿瘤、神经系统及心血管系统等方面的应用进展。     

动物发育过程中热休克基因的表达

本文综述了动物发育过程中热休克基因的表达及热休克蛋白质的合成与生物耐热性的相互关系。动物发育过程中热休克基因的表达具有阶段依赖性。热休克蛋白质的合成与生物耐热性的获得呈正相关。     

人热休克因子1突变体的应用研究进展

热休克因子1是调节应激反应的主要转录因子,它在应激条件下可被活化。通过基因突变得到正显性和负显性热休克因子1,它们不需要外界条件刺激就分别具有启动热休克蛋白的表达或竞争抑制内源热休克因子1活性的能力。目前,已有多个热休克因子1的突变体应用于疾病研究。介绍了热休克因子1的结构和活化途径,以及热休克因子1突变体在肿瘤、神经系统及心血管系统等方面的应用进展。     

热休克蛋白、蛋白水解酶和磷酸酶在大鼠肝再生中的含量和活性变化

本文以２／３肝切除（ｐａｒｔｉａｌ ｈｅｐａｔｅｃｔｏｍｙ,ＰＨ）大鼠为模型,探讨了ＰＨ后酸性和碱性磷酸酶（ａｃｉｄ ａｎｄ ａｌｋａｌｉｎｅ ｐｈｏｓｐｈａｔａｓｅｓ,ＡＣＰ和ＡＫＰ）,构成性热休克蛋白７０／诱导性热休克蛋白６８（ＨＳＣ７／ＨＳＰ６８）,酸性和中性蛋白水解酶在肝再生期间（０－１４４ｈ）的动态变化。结果显示,在肝切除后的肝再生期间;（１）ＡＣＰ和ＡＫＰ均出现两个活性高峰（４和４８ｈ     

大鼠肝生长发育过程中ACP、AKP、HSC70/HSP68和PCNA的变化(英文)

磷酸酶（ＡＣＰ、ＡＫＰ）在生物的机能分化中起重要作用,热休克蛋白（ＨＳＰｓ）是近几年发现的一类在胚胎发育、细胞生存中起重要作用的分子,无论是胚胎发育还是细胞结构和功能构建都和细胞增殖密切相关,增殖细胞核抗原（ＰＣＮＡ）是检测细胞增殖的良好指标。 本实验用组织化学、免疫组织化学、Ｗｅｓｔｅｒｎ印迹、酶的原位复性电泳、体视学分析等方法定性和定量分析了酸性磷酸酶（ＡＣＰ）（Ｆｉｇ．１＆２）、碱性磷酸酶（ＡＫＰ）（Ｆｉｇ．４＆５）、构成性热休克蛋白 ７０／诱导性热休克蛋白 ６８（ＨＳＣ７０／ＨＳＰ６８）（Ｆｉｇ．６）和ＰＣＮＡ（Ｆｉｇ．７＆８, Ｔａｂｌｅ１）在大鼠肝生长发育（从１４天胚胎到成体）过程中的动态变化。结果表明：（１）在大鼠肝生长发育过程中,ＡＣＰ有两个活性高峰期,其时段处于大鼠吃奶和吃饲料起始期（Ｆｉｇ．１＆２）;（２）在ＡＣＰ的第一个活性高峰期时,ＡＫＰ活性降低;而在ＡＣＰ的第二个活性高峰期时,正值ＡＫＰ的活性高峰期（Ｆｉｇ．３）;（３）ＡＣＰ活性高峰期也是ＰＣＮＡ含量高峰期;（４）ＨＳＣ７０／ＨＳＰ６８在刚断奶的幼鼠肝和成体肝中表达量较多,其他时段表达极少。根据上述结果推测：ＡＣＰ和ＰＣＮＡ通过调节细     

短隔连续部分肝切除（SISPH）对大鼠肝ACP、AKP、HSC70／HSP68和PCNA的影响

In this paper, the models of 36-4-4 SISPH and 4-36-36-36 SISPH were used to analyze the changes of activity and content of ACP, AKP, HSC70/HSP68 and PCNA in rat liver. The results showed that the activities of 140 kD ACP and AKP in SISPH were increased following the increase of SISPH number of times, but that of 160 kD ACP and AKP were decreased following the increase of SISPH number of times. The content of PCNA in 4-36-36-36 SISPH were more than that in 36-4-4 SISPH, in contrast for HSC70/HSP68 in these two models. Therefore, the content and activities of ACP, AKP, HSC70/HSP68 and PCNA could be strongly effected by SISPH number of times and SISPH methods. Its mechanisms and physiological significance were discussed.     

Molecular identification and expression of heat shock cognate 70 (HSC70) in the Pacific white shrimp Litopenaeus vannamei

Heat shock protein 70s (HSP70s) are fundamental chaperone proteins that are indispensable to most living organisms. In order to investigate the function of HSP70 and heat shock response in shrimp, a heat shock cognate (HSC70) gene of the white shrimp (Litopenaeus vannamei), containing a 1959-bp open reading frame, was cloned and characterized. The amino acid sequence, 71.5 kDa of molecular weight, shares 80-99.6% homology with 12 diverse species' HSP70s and HSC70s. In fact, some segments of the eukaryotic HSC70 sequence, such as ATP/GTP-binding site, cytoplasmic HSP70 C-terminal sequence, and GGMP/GAP repeats, are also found in the putative shrimp HSC70. Moreover, multi-tissue RT-PCR was performed to assay the basal expressions of HSC70 in the heart, gill, hepatopancreas, stomach, gut, and muscle. The results demonstrate that the basal expressions of HSC70 in theses organs are similar to that of beta-actin. Furthermore, quantitative real-time experiments showed that HSC70 was up-regulated in hepatopancreas (4.6-fold), stomach (5.9-fold), gut (2.6-fold), and muscle (3.5-fold) but not in the heart (1.7-fold) and gill (1.6-fold) after 2 h of heat shock. Nevertheless, the HSC70 was found to be highly expressed in the heart and gill following 6 h of heat shock. This suggests that HSC70 in white shrimp possess both short-term and long-term responses to heat shock stress, indicating this HSC70 may be a heat-dependent HSC70 member. Finally, we constructed an expression vector to generate HSC70 in Escherichia coli BL21, which displayed immune cross-reactivity with mouse HSP70 antibody. In conclusion, the identification and expression of white shrimp HSC70 gene present useful data for studying the molecular mechanism of heat shock response and the effect of heat shock proteins in shrimps' cytoprotection.     

Stress-induced release of HSC70 from human tumors

In this study, we demonstrate that the pro-inflammatory cytokine interferon-gamma (IFN-gamma) induces the active release of the constitutive form of the 70-kDa heat shock protein (HSC70) from K562 erythroleukemic cells. Treatment of K562 cells with IFN-gamma induced the upregulation of the inducible form of the 70-kDa heat shock protein (HSP70), but not the constitutive form of HSC70 within the cytosol, in a proteasome-dependent manner. In addition, IFN-gamma induced the downregulation of surface-bound HSC70, but did not significantly alter surface-bound HSP70 expression. These findings indicate that HSC70 can be actively released from tumor cells and is indicative of a previously unknown mechanism by which immune modulators stimulate the release of intracellular HSC70. This mechanism may account for the potent chaperokine activity of heat shock proteins recently observed during heat shock protein-based immunotherapy against a variety of cancers.     

Differential regulation of HSC70, HSP70, HSP90 alpha, and HSP90 beta mRNA expression by mitogen activation and heat shock in human lymphocytes

A subset of heat shock proteins, HSP90 alpha, HSP90 beta, and a member of the HSP70 family, HSC70, shows enhanced synthesis following mitogenic activation as well as heat shock in human peripheral blood mononuclear cells. In this study, we have examined expression of mRNA for these proteins, including the major 70-kDa heat shock protein, HSP70, in mononuclear cells following either heat shock or mitogenic activation with phytohemagglutinin (PHA), ionomycin, and the phorbol ester, tetradecanoyl phorbol acetate. The results demonstrate that the kinetics of mRNA expression of these four genes generally parallel the kinetics of enhanced protein synthesis seen following either heat shock or mitogen activation and provide clear evidence that mitogen-induced synthesis of HSC70 and HSP90 is due to increased mRNA levels and not simply to enhanced translation of preexisting mRNA. Although most previous studies have focused on cell cycle regulation of HSP70 mRNA, we found that HSP70 mRNA was only slightly and transiently induced by PHA activation, while HSC70 is the predominant 70-kDa heat shock protein homologue induced by mitogens. Similarly, HSP90 alpha appears more inducible by heat shock than mitogens while the opposite is true for HSP90 beta. These results suggest that, although HSP70 and HSC70 have been shown to contain similar promoter regions, additional regulatory mechanisms which result in differential expression to a given stimulus must exist. They clearly demonstrate that human lymphocytes are an important model system for determining mechanisms for regulation of heat shock protein synthesis in unstressed cells. Finally, based on kinetics of mRNA expression, the results are consistent with the hypothesis that HSC70 and HSP90 gene expression are driven by an IL-2/IL-2 receptor-dependent pathway in human T cells.     

Structural organization of the spinach endoplasmic reticulum-luminal 70-kilodalton heat-shock cognate gene and expression of 70-kilodalton heat-shock genes during cold acclimation.

The 70-kD heat-shock proteins (HSP70s) are encoded by a multigene family in eukaryotes. In plants, the 70-kD heat-shock cognate (HSC70) proteins are located in organellar and cytosolic compartments of cells in most tissues. Previous work has indicated that HSC70 proteins of spinach (Spinacia oleracea) are actively synthesized during cold-acclimating conditions. We have isolated, sequenced, and characterized cDNA and genomic clones for the endoplasmic reticulum (ER) luminal HSC70 protein (immunoglobulin heavy chain-binding protein; BiP) of spinach. The spinach ER-luminal HSC70 is a constitutively expressed gene consisting of eight exons. Spinach BiP mRNA appears to be up-regulated during cold acclimation but is not expressed during water stress or heat shock. In contrast to the differential regulation of mRNA, the ER-luminal HSC70 protein levels remain constant in response to various environmental stresses. Two other members of the spinach 70-kD heat-shock (HS70) multigene family also show differential expression in response to a variety of environmental stresses. A constitutively expressed cytosolic HSC70 protein in spinach appears also to be up-regulated in response to both cold-acclimating and heat-shock treatments. Spinach also contains a cold-shock-induced HS70 gene that is not expressed during heat shock or water stress. Since HSP70s are considered to be involved with the chaperoning and folding of proteins, the data further support the concept that they may be important for maintaining cellular homeostasis and proper protein biogenesis during cold acclimation of spinach.     

Interaction between SGT1 and cytosolic/nuclear HSC70 chaperones regulates Arabidopsis immune responses

The conserved eukaryotic protein SGT1 (for Suppressor of G2 allele of skp1) has characteristics of an HSP90 (for heat shock protein 90 kD) cochaperone and in plants regulates hormone responses and Resistance gene-triggered immunity. We affinity-purified SGT1-interacting proteins from Arabidopsis thaliana leaf extracts and identified by mass spectrometry cytosolic heat shock cognate 70 (HSC70) chaperones as the major stable SGT1 interactors. Arabidopsis SGT1a and SGT1b proteins associate with HSC70 in vivo and distribute with HSC70 in the cytosol and nucleus. An intact C-terminal SGT1-specific (SGS) domain that is required for all known SGT1b functions in immunity and development is needed for HSC70 interaction and for the nuclear accumulation of SGT1b. Interaction assays of transiently expressed proteins or their domains in Nicotiana benthamiana point to a role of SGT1 as a HSC70 cofactor. Expression of two HSC70 isoforms is upregulated by pathogen challenge, and while loss of function of individual cytosolic HSC70 genes has no defense phenotype, HSC70-1 overexpression disables resistance to virulent and avirulent pathogens. Moreover, mutations in SGT1b lead to a similar degree of heat shock tolerance as deregulation of HSC70-1. We conclude that an HSC70-SGT1 chaperone complex is important for multiple plant environmental responses and that the evolutionarily conserved SGS domain of SGT1 is a key determinant of the HSC70-SGT1 association.