热激蛋白90与热激应答

热激蛋白90(heat shock protein 90,HSP90)作为机体重要的分子伴侣之一,主要是维持机体内环境的稳态.在机体遭受内外界刺激时,体内氧化-抗氧化平衡失调诱发机体热激应答,诱导HSP90高表达来抵御刺激对机体造成的损伤.     

热激蛋白70与热激反应

热激反应是细胞保护的最原始机制之一。近年来,越来越多的研究证明热激蛋白作为一种自然机制参与细胞保护,而热激蛋白70家族在其中起重要作用,从而成为恶劣条件、手术过程以及同病原体的斗争中器官保护的重要机制之一。     

叶绿体小分子量热激蛋白介绍

本文对叶绿体小分子量热激蛋白的研究进行了简要的回顾和总结。叶绿体小分子量热激蛋白是热激蛋白超家族的成员,具有3个特殊的保守区域;当植物遇到热胁迫时,叶绿体小分子量热激蛋白能够保护光合系统Ⅱ和类囊体膜;初步分析了叶绿体小分子量热激蛋白与植物的耐热性和耐冷性关系以及其分子伴侣功能。     

叶绿体小分子量热激蛋白介绍

本文对叶绿体小分子量热激蛋白的研究进行了简要的回顾和总结.叶绿体小分子量热激蛋白是热激蛋白超家族的成员,具有3个特殊的保守区域;当植物遇到热胁迫时,叶绿体小分子量热激蛋白能够保护光合系统Ⅱ和类囊体膜;初步分析了叶绿体小分子量热激蛋白与植物的耐热性和耐冷性关系以及其分子伴侣功能.     

Heat Shock Factor 1 Drives Intergenic Association of Its Target Gene Loci upon Heat Shock

1. Download high-res image (280KB)
2. Download full-size image

     

人热休克蛋白70和热休克固有蛋白70的基因克隆和表达

目的:克隆人热休克蛋白70(HSP70)和热休克固有蛋白70(HSC70)基因,并在大肠杆茵中表达,获得重组蛋白.方法:用RT-PCR法从HepG2细胞中扩增HSP70及HSC70cDNA序列.测序后,将相应的cDNA插入pRSET-A表达载体,在大肠杆菌中表达,重组蛋白纯化后用SDS-PAGE及Western Blotting分析.结果:DNA序列结果显示.本研究所获得的HSP70及HSC70 cDNA序列与参考序列一致.将全长cDNA分别插入表达质粒后,转化BL21(DE3)细菌,在IPTG的诱导下,表达产物SDS-PAGE显示相应的分子量(70kDa)位置有明显的蛋白条带.Western Blotting结果证实了其为目的蛋白,经镍树脂柱纯化,获得了相应的重组多肽.结论:成功构建了原核表达重组质粒HSP70-pRSET-A和HSC70-pRSET-A,并获得了纯化的重组人HSP70和HSC70蛋白,为进一步研究这两种蛋白的结构、功能及临床应用奠定了基础.     

热激对水稻幼苗耐冷性及热激蛋白合成的诱导

萌发的水稻种子经42℃热激处理后其幼苗的耐冷性明显增强,膜伤害程度降低,脯氨酸含量增加,超氧物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性和抗氧化物质抗坏血酸含量增加,而膜脂过氧化的关键酶脂氧合酶(LOX)活性及其产物丙二醛(MDA)含量下降.并且热激诱导萌发的水稻胚合成78、70、64、60、46、38、24、17、16kD的热激蛋白(HSP),其中属于HSP70的内质网结合蛋白(BiP)的合成与水稻幼苗耐寒性的提高有关.     

热激蛋白70的研究进展

热激蛋白(HSP70)作为分子伴侣参与细胞内许多重要反应,从而对生物体起着重要的作用。随着研究的深入,其生物学功能不断被发现和利用的同时,HSP70的应用前景也变得越来越广泛。已有研究者对HSP70的生物学功能做了详细介绍,我们主要对近年来HSP70在医学及环境监测等方面的应用进行综述。     

Heat Shock Proteins and Circadian Rhythms

Significant circadian rhythms in heat shock gene expression were observed in a prokaryotic species (Synechocystis). In eukaryotes, in contrast, several heat shock genes (constitutive and inducible) were shown to be constantly expressed. A few cases of circadian expression of heat shock proteins (HSPs), however, have been reported. Significant circadian changes of thermotolerance were observed in yeast and several plant species. Higher thermo-tolerance can be attributed to a higher abundance of HSPs, but also to other adaptive mechanisms. Zeitgeber effects of temperature changes can be explained on the basis of their direct effects on the state variables of the clock gene (per, frq) expression and its negative feedback loop. Effects of increased HSP concentrations, as observed after heat shock, but also after light and serotonin (5HT), appear possible, in particular with respect to nuclear localization of the clock (PER) protein, but these effects have not been documented yet. Thus, the role of HSPs in the circadian clock system is little understood and, from our point of view, deserves more attention. (Chronobiology International, 13(4), 239-250, 1996)     

Biophoton Emission Induced by Heat Shock

Ultraweak biophoton emission originates from the generation of reactive oxygen species (ROS) that are produced in mitochondria as by-products of cellular respiration. In healthy cells, the concentration of ROS is minimized by a system of biological antioxidants. However, heat shock changes the equilibrium between oxidative stress and antioxidant activity, that is, a rapid rise in temperature induces biophoton emission from ROS. Although the rate and intensity of biophoton emission was observed to increase in response to elevated temperatures, pretreatment at lower high temperatures inhibited photon emission at higher temperatures. Biophoton measurements are useful for observing and evaluating heat shock.     

Heat Shock Response in Lactobacillus plantarum

Heat stress resistance and response were studied in strains of Lactobacillus plantarum. Stationary-phase cells of L. plantarum DPC2739 had decimal reduction times (D values) (D value was the time that it took to reduce the number of cells by 1 log cycle) in sterile milk of 32.9, 14.7, and 7.14 s at 60, 72, and 75°C, respectively. When mid-exponential-phase cells were used, the D values decreased. The temperature increases which caused a 10-fold reduction in the D value ranged from 9 to 20°C, depending on the strain. Part of the cell population treated at 72°C for 90 s recovered viability during incubation at 7°C in sterile milk for 20 days. When mid-exponential- or stationary-phase cells of L. plantarum DPC2739 were adapted to 42°C for 1 h, the heat resistance at 72°C for 90 s increased ca. 3 and 2 log cycles, respectively. Heat-adapted cells also showed increased growth at pH 5 and in the presence of 6% NaCl. Two-dimensional gel electrophoresis of proteins expressed by control and heat-adapted cells revealed changes in the levels of expression of 31 and 18 proteins in mid-exponential- and stationary-phase cells, respectively. Twelve proteins were commonly induced. Nine proteins induced in the heat-adapted mid-exponential- and/or stationary-phase cells of L. plantarum DPC2739 were subjected to N-terminal sequencing. These proteins were identified as DnaK, GroEL, trigger factor, ribosomal proteins L1, L11, L31, and S6, DNA-binding protein II HlbA, and CspC. All of these proteins have been found to play a role in the mechanisms of stress adaptation in other bacteria. Antibodies against GroES detected a protein which was induced moderately, while antibodies against DnaJ and GrpE reacted with proteins whose level of expression did not vary after heat adaptation. This study showed that the heat resistance of L. plantarum is a complex process involving proteins with various roles in cell physiology, including chaperone activity, ribosome stability, stringent response mediation, temperature sensing, and control of ribosomal function. The physiological mechanisms of response to pasteurization in L. plantarum are fundamental for survival in cheese during manufacture.     

热激蛋白47与胶原合成

热激蛋白47(heat shock protein 47,HSP470)作为胶原特异性的分子伴侣(molecular chaperone),能与前胶原特异性结合参与前胶原的折叠、修饰、转运等过程。两表达的时空一致性在培养细胞、胚胎发育细胞和组织纤维化进程中均得到证实,从而引起了人们对其在皮肤修复、抑制纤维化和肿瘤治疗等方面的重视。