Donahue Christine P, Ni Jake, Rozners Eriks, Glicksman Marcie A, Wolfe Michael S
Center for Neurologic Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
J Biomol Screen. 2007 Sep;12(6):789-99. doi: 10.1177/1087057107302676. Epub 2007 May 24.
Alternative splicing of tau exon 10 produces tau isoforms with either 3 (3R) or 4 (4R) repeated microtubule-binding domains. Increased ratios of 4R to 3R tau expression, above the physiological 1:1, leads to neurofibrillary tangles and causes neurodegenerative disease. An RNA stem loop structure plays a significant role in determining the ratio, with decreasing stability correlating with an increase in 4R tau mRNA expression. Recent studies have shown that aminoglycosides are able to bind and stabilize the tau stem loop in vitro, suggesting that other druglike small molecules could be identified and that such molecules might lead to decreased exon 10 splicing in vivo. The authors have developed a fluorescent high-throughput fluorescent binding assay and screened a library of approximately 110,000 compounds to identify candidate drugs that will bind the tau stem loop in vitro. In addition, they have developed a fluorescent-based RNA probe to assay the stabilizing effects of candidate drugs on the tau stem loop RNA. These assays should be applicable to the general problem of identifying small molecules that interact with mRNA secondary structures.
tau外显子10的可变剪接产生具有3个（3R）或4个（4R）重复微管结合结构域的tau异构体。4R与3R tau表达的比例增加，超过生理水平的1:1，会导致神经原纤维缠结并引发神经退行性疾病。一种RNA茎环结构在决定该比例中起重要作用，稳定性降低与4R tau mRNA表达增加相关。最近的研究表明，氨基糖苷类药物在体外能够结合并稳定tau茎环，这表明可以鉴定出其他类似药物的小分子，并且这类分子可能会导致体内外显子10剪接减少。作者开发了一种荧光高通量结合测定法，并筛选了一个约110,000种化合物的文库，以鉴定在体外能结合tau茎环的候选药物。此外，他们还开发了一种基于荧光的RNA探针，以检测候选药物对tau茎环RNA的稳定作用。这些测定法应适用于识别与mRNA二级结构相互作用的小分子这一普遍问题。
