Lisowiec Jolanta, Magner Dorota, Kierzek Elzbieta, Lenartowicz Elzbieta, Kierzek Ryszard
a Institute of Bioorganic Chemistry; Polish Academy of Sciences ; Noskowskiego, Poland.
RNA Biol. 2015;12(3):330-42. doi: 10.1080/15476286.2015.1017214.
Alternative splicing at the MAPT gene exon 10 yields similar levels of the 3R and 4R tau protein isoforms. (1) The presence of mutations, particularly in exon 10 and intron 10-11, changes the quantity of tau isoforms. Domination each of the isoform yields tau protein aggregation and frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17). Here, we report for the first time the secondary structure of the 194/195 nucleotide region for the wild type (WT) and 10 mutants of the MAPT gene pre-mRNA determined using both chemical and microarray mapping. Thermodynamic analyses indicate that single nucleotide mutations in the splicing regulatory element (SRE) that form a hairpin affect its stability by up to 4 and 7 kcal/mol. Moreover, binding the regulatory hairpin of small molecule ligands (neomycin, kanamycin, tobramycin and mitoxantrone) enhance its stability depending on the nature of the ligands and the RNA mutations. Experiments using the cos-7 cell line indicate that the presence of ligands and modified antisense oligonucleotides affect the quantity of 3R and 4R isoforms. This finding correlates with the thermodynamic stability of the regulatory hairpin. An alternative splicing regulation mechanism for exon 10 is postulated based on our experimental data and on published data.
微管相关蛋白tau（MAPT）基因第10外显子的可变剪接产生相似水平的3R和4R tau蛋白异构体。（1）突变的存在，尤其是第10外显子和第10 - 11内含子中的突变，会改变tau异构体的数量。每种异构体占主导都会导致tau蛋白聚集以及与17号染色体相关的额颞叶痴呆和帕金森综合征（FTDP - 17）。在此，我们首次报告了使用化学和微阵列图谱测定的野生型（WT）和MAPT基因前体mRNA的10种突变体的194/195核苷酸区域的二级结构。热力学分析表明，形成发夹结构的剪接调节元件（SRE）中的单核苷酸突变会使其稳定性改变高达4至7千卡/摩尔。此外，结合小分子配体（新霉素、卡那霉素、妥布霉素和米托蒽醌）的调节发夹会根据配体的性质和RNA突变增强其稳定性。使用cos - 7细胞系进行的实验表明，配体和修饰的反义寡核苷酸的存在会影响3R和4R异构体的数量。这一发现与调节发夹的热力学稳定性相关。基于我们的实验数据和已发表的数据，推测了第10外显子的一种可变剪接调控机制。
