Polenkowski Mareike, Allister Aldrige Bernardus, Burbano de Lara Sebastian, Pierce Andrew, Geary Bethany, El Bounkari Omar, Wiehlmann Lutz, Hoffmann Andrea, Whetton Anthony D, Tamura Teruko, Tran Doan Duy Hai
Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover D-30623, Germany.
Institut für Zellbiochemie, Medizinische Hochschule Hannover, Hannover D-30623, Germany.
iScience. 2022 Dec 9;26(1):105784. doi: 10.1016/j.isci.2022.105784. eCollection 2023 Jan 20.
THOC5, a member of the THO complex, is essential for the 3'processing of some inducible genes, the export of a subset of mRNAs and stem cell survival. Here we show that THOC5 depletion results in altered 3'cleavage of >50% of mRNAs and changes in RNA polymerase II binding across genes. THOC5 is recruited close to high-density polymerase II sites, suggesting that THOC5 is involved in transcriptional elongation. Indeed, measurement of elongation rates demonstrated decreased rates in THOC5-depleted cells. Furthermore, THOC5 is preferentially recruited to its target genes in slow polymerase II cells compared with fast polymerase II cells. Importantly chromatin-associated THOC5 interacts with CDK12 (a modulator of transcription elongation) and RNA helicases DDX5, DDX17, and THOC6 only in slow polymerase II cells. The CDK12/THOC5 interaction promotes CDK12 recruitment to R-loops in a THOC6-dependent manner. These data demonstrate a novel function of THOC5 in transcription elongation.
THOC5是THO复合物的成员之一，对某些诱导型基因的3'加工、一部分mRNA的输出以及干细胞存活至关重要。我们在此表明，THOC5缺失会导致超过50%的mRNA的3'切割改变，以及全基因组范围内RNA聚合酶II结合的变化。THOC5被招募至高密度聚合酶II位点附近，这表明THOC5参与转录延伸。事实上，对延伸速率的测量显示，THOC5缺失的细胞中延伸速率降低。此外，与快速聚合酶II细胞相比，THOC5在慢速聚合酶II细胞中更优先被招募至其靶基因。重要的是，仅在慢速聚合酶II细胞中，与染色质相关的THOC5与CDK12（转录延伸调节剂）以及RNA解旋酶DDX5、DDX17和THOC6相互作用。CDK12/THOC5相互作用以THOC6依赖的方式促进CDK12招募至R环。这些数据证明了THOC5在转录延伸中的新功能。
