Arabidopsis mRNA export factor tho5ab: molecular interactions and role in heat stress responses

A central function in linking RNA polymerase II transcription and pre-mRNA processing with mRNA export is executed by the transcription and export (TREX) complex. TREX consists of a hexameric core termed THO that associates with various combinations of additional proteins giving rise to alternative versions of TREX. Cell fractionation in combination with transcript profiling demonstrated that THO5 a subunit of the THO complex is required for export of a subset of mRNAs . Overall design: To investigate export defects in tho5ab mutants upon heat stress RNA was isolated in nuclear and cytoplasmic fractions at 21° C and 37° C for 3h from wild type Arabidopsis Thaliana (Col-0) and tho5ab mutants

将RNA聚合酶II（RNA polymerase II）转录、前体mRNA（pre-mRNA）加工与mRNA输出相连接的核心生物学功能，由转录-输出复合物（transcription and export complex，TREX）执行。
TREX由被称为THO复合物（THO complex）的六聚体核心组成，该核心可与多种不同组合的附加蛋白结合，进而形成TREX的多种可变亚型。通过细胞分级分离技术联合转录组分析，研究证实THO5——THO复合物的一个亚基——对于部分mRNA的输出是必需的。
总体实验设计：为探究tho5ab突变体在热胁迫下的mRNA输出缺陷，研究人员分别在21℃与37℃条件下处理野生型拟南芥（Arabidopsis thaliana，Col-0）及tho5ab突变体3小时，随后分离其细胞核与细胞质组分中的RNA。