Dentatorubral-pallidoluysian atrophy protein interacts through a proline-rich region near polyglutamine with the SH3 domain of an insulin receptor tyrosine kinase substrate.
Dentatorubral-pallidoluysian atrophy protein interacts through a proline-rich region near polyglutamine with the SH3 domain of an insulin receptor tyrosine kinase substrate.
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DOI：
10.1093/hmg/8.6.947
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发表时间：
1999-06
影响因子：
3.5
通讯作者：
Y. Okamura-Oho;T. Miyashita;K. Ohmi;M. Yamada
中科院分区：
文献类型：
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作者：
Y. Okamura-Oho;T. Miyashita;K. Ohmi;M. Yamada
齿状核-苍白球萎缩症是一种常染色体显性遗传性神经遗传性疾病，与CAG/谷氨酰胺重复序列扩张相关。虽然DRPLA基因普遍表达，但神经元死亡发生在大脑的特定解剖区域。这预示着DRLA蛋白与其他蛋白相互作用，这些相互作用可能在发病机制中发挥作用。在这里，我们描述了一种与DRPLA产品结合的蛋白质。用酵母双杂交系统分离的克隆之一被鉴定为53 kDa胰岛素受体酪氨酸激酶底物蛋白(IRSP53)的人类同源物。该基因通过差异剪接产生两种形式的mRNA，分别编码552和521个氨基酸。较长的形式主要在脑内表达，较短的形式主要在其他组织中表达。在胰岛素或胰岛素样生长因子1刺激培养细胞时，产物被磷酸化。通过与抗体的免疫共沉淀以及表达工程构建物的细胞中核周椭圆点的共同定位，证实了DRLA蛋白与IRSP53的结合。DRLA蛋白聚谷氨酰胺束附近的一个富含脯氨酸的区域和IRSP53的SH3结构域参与了结合。延伸的聚谷氨酰胺束显著降低酵母细胞的结合能力，但在体外结合试验中不会。通过酵母杂交系统检测到的IRSP53和其他蛋白质的鉴定表明，DRPLA在与胰岛素/IGF-1偶联的信号转导途径中发挥作用。
Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neuro degrees enerative disorder associated with CAG/glutamine repeat expansion. While the DRPLA gene is ubiquitously expressed, neuron death occurs in specific anatomical areas of the brain. This predicts that the DRPLA protein interacts with other proteins and that these interactions may play a role in pathogenesis. Here, we describe a protein that binds to the DRPLA product. One of the clones isolated with a yeast two-hybrid system was identified as a human homolog of the insulin receptor tyrosine kinase substrate protein of 53 kDa (IRSp53). The gene produced two mRNA forms by differential splicing and encoded 552 and 521 amino acids, respectively. The longer form was mainly expressed in the brain and the shorter one in other tissues. The products were phosphorylated upon stimulation of cultured cells with insulin or insulin-like growth factor 1. Binding of the DRPLA protein to IRSp53 was ascertained by co-immunoprecipitation with antibodies and also by co-localization in perinuclear oval dots in cells expressing engineered constructs. A proline-rich region near the polyglutamine tract of the DRPLA protein and the SH3 domain of IRSp53 were involved in the binding. An extended polyglutamine tract significantly reduced binding ability in yeast cells, but not in in vitro binding assays. The identification of IRSp53 and other proteins detected by the yeast hybrid system predicts that DRPLA functions in a signal transduction pathway coupled with insulin/IGF-1.