Evidence from antibody studies that the CAG repeat in the Huntington disease gene is expressed in the protein.
Evidence from antibody studies that the CAG repeat in the Huntington disease gene is expressed in the protein.
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抗体研究的证据表明亨廷顿病基因中的 CAG 重复在蛋白质中表达。
DOI：
10.1093/hmg/4.3.465
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发表时间：
1995
影响因子：
3.5
通讯作者：
Myers,RM
中科院分区：
文献类型：
--
作者：
Jou,YS;Myers,RM
神经退行性疾病亨廷顿病（HD）似乎是由位于基因5 '端附近的三核苷酸CAG重复次数增加引起的。cDNA和基因的核苷酸序列预测HD蛋白的分子量为347000（3144个氨基酸），CAG重复序列编码从氨基端开始17个氨基酸的聚谷氨酰胺片段。由于CAG重复序列在该疾病的病因学中起着如此关键的作用，我们试图获得证据，证明多谷氨酰胺片段确实存在于蛋白质中。我们利用预测位于11-19个氨基酸位置的hd1肽（FESLKSFQQ）和预测位于2531-2539个氨基酸位置的hd2肽（QQPRNKPLK）在NZW兔体内诱导多克隆抗体。这两种抗体在Western blots上识别来自人脑组织和人和猴细胞系的细胞裂解液中约350 kDa的蛋白质，包括来自该疾病的杂合和纯合个体的细胞。这些结果表明，这些细胞中的HD蛋白含有预测的氨基末端片段，由此推断，含有聚谷氨酰胺片段，并且即使只有突变基因拷贝存在，该蛋白也会表达。有趣的是，在含有啮齿动物细胞系裂解物的Western blots上，hd1-peptide抗体不能识别HD蛋白，而hd2-peptide抗体却能。这种区分提供了一种有用的方法来测定人类HD蛋白在啮齿动物细胞背景中的存在。
The neurodegenerative disorder Huntington disease (HD) appears to be caused by an increase in the number of repeats of the trinucleotide CAG located near the 5′ end of the gene. The nucleotide sequences of the cDNA and the gene predict that the HD protein has a molecular weight of 347 000 (3144 amino acids) and that the CAG repeats encode a segment of polyglutamine beginning 17 amino acids from the amino terminus. Because the CAG repeat plays such a critical role in the etiology of the disease, we sought to obtain evidence that the polyglutamine segment is indeed present in the protein. We used two peptides, hd1-peptide (FESLKSFQQ), predicted to lie at amino acid positions 11–19, just amino-terminal to the polyglutamine segment, and hd2-peptide (QQPRNKPLK), predicted to lie at amino acid positions 2531–2539, to induce polyclonal antibodies in NZW rabbits. Both antibodies recognize a protein on Western blots of about 350 kDa in cell lysates from human brain tissue and human and monkey cell lines, including cells from individuals heterozygous and homozygous for the disease. These results suggest that the HD protein in these cells contains the predicted amino terminal segment, and by inference, the segment of polyglutamine, and that the protein is expressed even when only mutant copies of the gene are present. Interestingly, the antibody to hd1-peptide does not recognize the HD protein on Western blots containing lysates from rodent cell lines, whereas the antibody to hd2-peptide does. This discrimination provides a useful means to assay for the presence of the human HD protein in a rodent cell background.