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【medical-news】分子伴侣保护细胞
分子伴侣保护细胞
Medical Research News
Published: Wednesday, 13-Sep-2006
Falsely folded proteins and their aggregations in neurons are considered to be the cause of neurodegenerative diseases, among them Chorea Huntington.
在神经元内错误折叠的蛋白质以及它们的聚集被认为是神经退行性疾病的病因，比如舞蹈病。
Dr. Ulrich Hartl from the Max Planck Institute for Biochemistry in Munich has identified a new family of molecular chaperones that prevent proteins from "misbehaving" and ensure that they fold properly.
来自慕尼黑Max Planck生化研究所的Ulrich博士已经证实一系列新分子伴侣族能够阻止蛋白的错误行为和确保蛋白的正确折叠。
This he reported at the International Conference "Neurodegenerative Diseases: Molecular Mechanisms in a Functional Genomics Framework" in the Max Delbr communications Center (MDC.C) in Berlin, Germany.
他在德国柏林的Max Delbr交流中心举行的名为神经退行性疾病-功能基因组学框架的分子学机制的国际会议上作了报告。
The new family of chaperones, called TriC for short, supports another family of chaperones which Dr. Hartl had discovered a few years ago and which belongs to the family of heat shock proteins (Hsp-70). Both families ensure that proteins fold correctly and that they neither aggregate, nor kill nerve cells.
这个新的分子伴侣家族简称为TriC，支持Hartl博士多年前发现的另一属于热休克蛋白家族分子伴侣族。这两个家族都能够使蛋白正确折叠，它们也不聚集或者杀伤细胞。
Proteins, the building material and the machines of life, can only become active when they fold and take on a three-dimensional structure. Scientists assume that insoluble protein aggregations (plaques) in nerve cells trigger Chorea Huntington, an inherited disease.
蛋白质，生命的组成物质和机器，只有在正确折叠形成三维结构时才会具有活性。科学家推定在神经细胞中不溶蛋白质的聚集（斑块）能够触发舞蹈症（一种遗传性疾病）的发生。
The disease is characterized by jerky, uncontrolled movements of the body and face and, therefore, is called Chorea (Old Greek for "dance") Huntington. Its scientific name goes back to the New York physician George Huntington who was the first to describe the deadly disease in 1872.
这种疾病以抽搐，身体和面部不受控制的运动为特征，因此，被称为亨廷顿舞蹈症（Chorea旧希腊文意味舞蹈）。它的学名来源于纽约的乔治亨廷顿医生，他首次在1872年描述了这种致死性疾病。
There is no cure for the disease and it can neither be stopped nor reversed. Researchers estimate that 1 in 10,000 persons is effected. So far 30,000 cases are known in the United States, 10, 000 in Canada, and 8,000 in Germany.
还没有任何方法治疗这种疾病，也不能使之停止发展和逆转。研究者估计大约有万分之一的人患有此病。目前已知在美国有3万名 ，加拿大有一万，而德国有8千名患者。
In 1993, researchers discovered the gene which produces the mutant protein huntingtin. This protein is considered to be the cause of Chorea Huntington. It is deposited in the nucleus of the nerve cells.
1993年研究者发现了编码突变亨廷顿蛋白的基因。这种蛋白被认为是引起亨廷顿舞蹈症的病因。她聚集在神经细胞的胞核内。
In 1997, Dr. Erich Wanker, then at the Max-Planck-Institute for molecular Genetics, Berlin, now at the Max Delbr?nter for Molecular Medicine (MDC), Berlin-Buch, was able to show that these aggregations consist of falsely folded huntingtin molecules.
1997年，来自德国的Max-Planck分子基因研究所的 Erich Wanker博士，现在供职于柏林Max Delb分子医学中心，发现了包含错误折叠的亨廷顿蛋白分子的聚集物。
The protein production units in nerve cells add too many glutamin building blocks to the amino acid sequence of the huntingtin protein, resulting in polyglutamin chains that are siginificantly longer than normal ones. As a result, the protein loses its normal structure and can no longer be degraded. Scientists assume that these protein aggregations are toxic for nerve cells.
神经细胞中蛋白的生产单元将许多谷氨酸结构加入到亨廷顿蛋白的氨基酸序列中，造成许多多谷氨酸链致使其长于正常的蛋白。这使得蛋白质失去了其正常的结构而且不再被降解。科学家们推定这些蛋白聚集物对神经细胞是有毒性的。
However, it remains unclear as to how and by what mechanism these aggregations effect the nerve cells which lose their their normal function and eventually die. "There are mainly two hypotheses", said Dr. Hartl. "In one model, neurotoxicity results from the ability of polyglutamin-expanded proteins to recruit other important cellular proteins with short polyglutamin stretches into the aggregates." In the other model, aggregating polyglutamin proteins cause a partial inhibition of the garbage disposal of the cells, the ubiquitin-proteasome system.
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作者:admin@医学,生命科学 2010-12-29 17:14
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