共查询到19条相似文献,搜索用时 80 毫秒
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分子伴侣介导的细胞自噬(chaperone-mediated autophagy,CMA)是通过溶酶体途径选择性降解胞质中带KFERQ-序列的蛋白质。CMA不仅为细胞在持久饥饿状态下提供能量,还在氧化性损伤保护、维持细胞内环境稳态等方面发挥作用。此外,CMA功能障碍还与某些疾病的发生有关。该文简要综述了这方面的研究进展。 相似文献
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线虫中的小分子热休克蛋白HSP12.1具有类分子伴侣活性 总被引:1,自引:0,他引:1
很多种类的小分子热休克蛋白(small heat shock protein,sHSP)都能在胁迫条件下抑制蛋白质的聚集,显示出了类分子伴侣活性,这种活性是ATP非依赖型的.从已经进行的实验发现,线虫C.elegans中最小的小分子热休克蛋白家族成员HSP12.1具有类分子伴侣活性,以胰岛素、乙醇脱氢酶和溶菌酶做底物发现HSP12.1能够一定程度地抑制底物的热聚集,虽然这种活性较一些经典的分子伴侣蛋白(线虫中的HSP16.1)要低.与此不同,另外3种和其分子质量相近的sHSP12s(HSP12.2、HSP12.3和HSP12.6)却没有检测出这样的类分子伴侣活性,虽然它们在一级结构上有很高的相似性.另外,在大肠杆菌中表达HSP12.1蛋白能够提高细菌在高温环境下的生存率,45℃处理后的生存率比未表达HSP12.1的菌高4倍左右,不过在线虫中是否发挥同样的功能还不是很清楚.从研究结果来看,C端“尾巴”结构域对sHSP发挥类分子伴侣活性不是必要的,在HSP12.1中没有C端“尾巴”结构域也有类分子伴侣活性就证明了这一点.N端结构域可能在发挥类分子伴侣活性中发挥比较重要的作用,当然α-crystallin结构域也可能参与到发挥这样的功能当中. 相似文献
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辅助伴侣分子Cdc37蛋白的研究进展 总被引:1,自引:0,他引:1
细胞分裂周期蛋白Cdc37最初是在芽殖酵母中发现的细胞周期相关蛋白。随后的研究表明Cdc37具有伴侣分子活性,可以特异地募集一系列的蛋白激酶结合到热激蛋白90(Hsp90)上,形成特定的分子伴侣复合体,参与维持蛋白的稳定性和激酶活性。Cdc37参与了细胞内的多项生命活动,在细胞周期、信号转导和基因表达中都起着重要的作用。由于Cdc37在肿瘤组织中特异性地高表达,使其成为肿瘤治疗中一个重要的分子靶点。 相似文献
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玉米胚乳细胞中纯化的细胞质Hsp70蛋白有低水平的ATPase 活性,它在50 ℃、pH5 .8 、20 mmol/L的KCl 条件下活性最高,Ca2+和Mg2+ 抑制其活性。大肠杆菌DnaJ蛋白能将玉米细胞质Hsp70 的ATPase 活性提高6倍,而GrpE 蛋白对其影响很小。8 种不同的人工合成多肽均能刺激该蛋白的ATPase 活性,增加幅度从2 .5 倍到10 倍不等。亲水性不同的氨基酸对Hsp70 的ATPase 活性影响不同。玉米细胞质Hsp70 是一个三磷酸核苷酸酶,除ATP 外,它还能催化UTP、GTP、CTP和ITP的水解 相似文献
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玉米细胞质分子伴侣Hsp70的ATPase活性 总被引:1,自引:0,他引:1
玉米胚乳细胞中纯化的细胞质Hsp70蛋白有低水平的ATPase活性,它在50℃、PH5.8、20mmol/L的KCl条件下活性最高,Ca^2+和Mg^2+抑制其活性。大肠杆菌DnaJ蛋白能将玉米细胞质Hsp70的ATPase活性提高6倍,而GrpE蛋白对其影响很小。8种不同的人工合成多肽均能刺激该蛋白折ATPase活性,增加幅度从2.5倍到10倍痫水性不同的氨基酸对Hsp70的ATPase活性影响 相似文献
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Structural and functional homology between periplasmic bacterial molecular chaperones and small heat shock proteins 总被引:1,自引:0,他引:1
Vladimir P. Zav'yalov Galina A. Zav'yalova Alexander I. Denesyuk Matthias Gaestel Timo Korpela 《FEMS immunology and medical microbiology》1995,11(4):265-272
Abstract The periplasmic Yersinia pestis molecular chaperone Caf1M belongs to a superfamily of bacterial proteins for one of which (PapD protein of Escherichia coli ) the immunoglobulin-like fold was solved by X-ray analysis. The N-terminal domain of Caf1M was found to share a 20% amino acid sequence identity with an inclusion body-associated protein IbpB of Escherichia coli . One of the regions that was compared, was 32 amino acids long, and displayed more than 40% identity, probability of random coincidence was 1.2 × 10−4 . IbpB is involved in a superfamily of small heat shock proteins which fulfil the function of molecular chaperone. On the basis of the revealed homology, an immunoglobulin-like one-domain model of IbpB three-dimensional structure was designed which could be a prototype conformation of sHsp's. The structure suggested is in good agreement with the known experimental data obtained for different members of sHsp's superfamily. 相似文献
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To find the road traveled to tumor immunity: the trafficking itineraries of molecular chaperones in antigen-presenting cells 总被引:3,自引:0,他引:3
Molecular chaperones, both endoplasmic reticulum and cytosol derived, have been identified as tumor rejection antigens; in animal models, they can elicit prophylactic and therapeutic immune responses against their tumor of origin. Chaperone immunogenic activity derives from three principal characteristics: they bind an array of immunogenic (poly)peptides, they can be efficiently internalized by professional antigen-presenting cells, and once internalized, they traffic to a subcellular compartment(s) where peptide release can occur. Within the antigen-presenting cell, chaperone-derived peptides can be assembled onto major histocompatibility class I molecules for presentation at the antigen-presenting cell surface, thereby yielding the requisite and specific CD8+ T-cell responses that contribute to the process of tumor rejection. Though it is clear that chaperones, in particular GRP94 (gp96), calreticulin and Hsp70, can elicit cellular immune responses, the subcellular basis of chaperone processing by antigen-presenting cells remains mysterious. In this review, we discuss recent reports describing the identification of a chaperone internalization receptor and the physiological release of chaperones from necrotic cells, and we present views on the trafficking pathways within antigen-presenting cells that may function to deliver the chaperone-associated peptides to subcellular organelles for their subsequent exchange onto major histocompatibility complex molecules. 相似文献
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Stephan N. Witt 《Biopolymers》2010,93(3):218-228
Because over expression of Hsp70 molecular chaperones suppresses the toxicity of aberrantly folded proteins that occur in Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis, and various polyQ‐diseases (Huntington's disease and ataxias), Hsp70 is garnering attention as a possible therapeutic agent for these various diseases. Here, I review progress in this fascinating field of molecular chaperones and neurodegeneration and describe our current understanding of the mechanisms by which Hsp70 protects cells from the PD‐related protein called alpha‐synuclein (α‐syn). © 2009 Wiley Periodicals, Inc. Biopolymers 93: 218–228, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com 相似文献
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Masoud Nouri-Vaskeh Leila Alizadeh Khalil Hajiasgharzadeh Ahad Mokhtarzadeh Monireh Halimi Behzad Baradaran 《Journal of cellular physiology》2020,235(12):9110-9120
Misfolded proteins have enhanced formation of toxic oligomers and nonfunctional protein copies lead to recruiting wild-type protein types. Heat shock protein 90 (HSP90) is a molecular chaperone generated by cells that are involved in many cellular functions through regulation of folding and/or localization of large multi-protein complexes as well as client proteins. HSP90 can regulate a number of different cellular processes including cell proliferation, motility, angiogenesis, signal transduction, and adaptation to stress. HSP90 makes the mutated oncoproteins able to avoid misfolding and degradation and permits the malignant transformation. As a result, HSP90 is an important factor in several signaling pathways associated with tumorigenicity, therapy resistance, and inhibiting apoptosis. Clinically, the upregulation of HSP90 expression in hepatocellular carcinoma (HCC) is linked with advanced stages and inappropriate survival in cases suffering from this kind of cancer. The present review comprehensively assesses HSP90 functions and its possible usefulness as a potential diagnostic biomarker and therapeutic option for HCC. 相似文献
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植物胞质雄性不育及育性恢复的分子机制研究进展(综述) 总被引:3,自引:0,他引:3
本文从与雄性不育有关的线粒体基因引起雄性不育的机理、雄性不育育性恢复机制以及育性恢复基因的克隆等方面,介绍国内外对植物细胞质雄性不育分子机理的研究进展,并对今后的研究进行讨论。 相似文献
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The role of molecular chaperones in human misfolding diseases 总被引:1,自引:0,他引:1
Sarah A. Broadley 《FEBS letters》2009,583(16):2647-144
Human misfolding diseases arise when proteins adopt non-native conformations that endow them with a tendency to aggregate and form intra- and/or extra-cellular deposits. Molecular chaperones, such as Hsp70 and TCP-1 Ring Complex (TRiC)/chaperonin containing TCP-1 (CCT), have been implicated as potent modulators of misfolding disease. These chaperones suppress toxicity of disease proteins and modify early events in the aggregation process in a cooperative and sequential manner reminiscent of their functions in de novo protein folding. Further understanding of the role of Hsp70, TRiC, and other chaperones in misfolding disease is likely to provide important insight into basic pathomechanistic principles that could potentially be exploited for therapeutic purposes. 相似文献