A cellular assay distinguishes normal and mutant TIGR/myocilin protein
A cellular assay distinguishes normal and mutant TIGR/myocilin protein
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DOI：
10.1093/hmg/8.12.2221
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发表时间：
1999-11-01
影响因子：
3.5
通讯作者：
Vollrath, D
中科院分区：
文献类型：
--
作者：
Zhou, ZH;Vollrath, D
青光眼是一种致盲性眼病，全世界约有7000万人患病。基因TIGR/MYOC中的突变已显示在选定的家族中引起疾病的最常见形式，原发性开角型青光眼。已在2-4%的散发性原发性开角型青光眼病例中发现该基因的氨基酸序列变体，大多数变异是罕见的，并且通常难以仅基于基因组中的相对频率来明确区分有害突变和良性变异。患者和对照组。TIGR/myocilin蛋白的功能是未知的，并且缺乏对变体进行功能分类的测定。我们试图开发一种生物化学测定来区分不同形式的TIGR/肌球蛋白。我们研究了通过转染在培养细胞中表达的突变体和正常形式的蛋白质的Triton X-100去污剂溶解性特征。我们观察到两种类型的TIGR/肌球蛋白的行为的明显差异;所有确认的测试的突变体蛋白质基本上是Triton不溶的，而正常蛋白质和对照是完全可溶的。我们还测试了七个模糊的变体蛋白，并根据它们的Triton溶解度将它们分类为突变或正常，结果在某些情况下验证了这些变体的早期分类，而在其他情况下则与之相矛盾。据我们所知，Triton溶解度是TIGR/myocilin的突变体和正常形式的性质的一般差异的第一个例子。我们已经开发的测定将用于从突变的位置辨别蛋白质功能信息，将有助于对具有TIGR/myocilin变体的个体进行遗传咨询，并且可以提供理解TIGR/MYOC中的突变引起青光眼的机制的线索。
Glaucoma is a blinding eye disease that affects similar to 70 000 000 people world-wide. Mutations in the gene TIGR/MYOC have been shown to cause the most common form of the disease, primary open angle glaucoma, in selected families, Amino acid sequence variants of the gene have been found in 2-4% of sporadic primary open angle glaucoma cases, Most variants are rare and it is often difficult to definitively distinguish between a deleterious mutation and a benign variant solely on the basis of relative frequencies in patient and control groups. The function of the TIGR/myocilin protein is unknown and an assay to functionally classify variants is lacking. We sought to develop a biochemical assay to distinguish different forms of TIGR/myocilin. We investigated the Triton X-100 detergent solubility characteristics of mutant and normal forms of the protein, expressed by transfection in cultured cells, We observed a clear difference in the behavior of the two types of TIGR/myocilin; all confirmed mutant proteins tested were substantially Triton insoluble, while normal protein and controls were completely soluble. We also tested seven ambiguous variant proteins and classified them as mutant or normal on the basis of their Triton solubility, The results in some cases validated, and in other cases contradicted, earlier classifications of these variants. To our knowledge, Triton solubility is the first example of a general difference in the properties of mutant and normal forms of TIGR/myocilin, The assay we have developed will be useful for discerning protein functional information from the location of mutations, will aid genetic counseling of individuals with TIGR/myocilin variants and may provide a clue to understanding a mechanism by which mutations in TIGR/MYOC cause glaucoma.