Oegema Renske, Baillat David, Schot Rachel, van Unen Leontine M, Brooks Alice, Kia Sima Kheradmand, Hoogeboom A Jeannette M, Xia Zheng, Li Wei, Cesaroni Matteo, Lequin Maarten H, van Slegtenhorst Marjon, Dobyns William B, de Coo Irenaeus F M, Verheijen Frans W, Kremer Andreas, van der Spek Peter J, Heijsman Daphne, Wagner Eric J, Fornerod Maarten, Mancini Grazia M S
Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands.
Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston TX, United States of America.
PLoS Genet. 2017 May 25;13(5):e1006809. doi: 10.1371/journal.pgen.1006809. eCollection 2017 May.
Integrator is an RNA polymerase II (RNAPII)-associated complex that was recently identified to have a broad role in both RNA processing and transcription regulation. Importantly, its role in human development and disease is so far largely unexplored. Here, we provide evidence that biallelic Integrator Complex Subunit 1 (INTS1) and Subunit 8 (INTS8) gene mutations are associated with rare recessive human neurodevelopmental syndromes. Three unrelated individuals of Dutch ancestry showed the same homozygous truncating INTS1 mutation. Three siblings harboured compound heterozygous INTS8 mutations. Shared features by these six individuals are severe neurodevelopmental delay and a distinctive appearance. The INTS8 family in addition presented with neuronal migration defects (periventricular nodular heterotopia). We show that the first INTS8 mutation, a nine base-pair deletion, leads to a protein that disrupts INT complex stability, while the second missense mutation introduces an alternative splice site leading to an unstable messenger. Cells from patients with INTS8 mutations show increased levels of unprocessed UsnRNA, compatible with the INT function in the 3'-end maturation of UsnRNA, and display significant disruptions in gene expression and RNA processing. Finally, the introduction of the INTS8 deletion mutation in P19 cells using genome editing alters gene expression throughout the course of retinoic acid-induced neural differentiation. Altogether, our results confirm the essential role of Integrator to transcriptome integrity and point to the requirement of the Integrator complex in human brain development.
整合酶是一种与RNA聚合酶II（RNAPII）相关的复合物，最近被发现它在RNA加工和转录调控中都发挥着广泛作用。重要的是，其在人类发育和疾病中的作用目前在很大程度上尚未得到探索。在此，我们提供证据表明，双等位基因整合酶复合物亚基1（INTS1）和亚基8（INTS8）基因突变与罕见的隐性人类神经发育综合征相关。三名荷兰血统的无关个体表现出相同的纯合截短型INTS1突变。三名兄弟姐妹携带复合杂合性INTS8突变。这六名个体的共同特征是严重的神经发育迟缓以及独特的外貌。INTS8家族的成员还表现出神经元迁移缺陷（脑室周围结节性异位）。我们发现，第一个INTS8突变，即一个9个碱基对的缺失，导致一种破坏INT复合物稳定性的蛋白质，而第二个错义突变引入了一个导致信使不稳定的可变剪接位点。来自INTS8突变患者的细胞显示未加工的UsnRNA水平升高，这与INT在UsnRNA 3'端成熟中的功能相符，并且在基因表达和RNA加工方面表现出显著破坏。最后，利用基因组编辑在P19细胞中引入INTS8缺失突变会在视黄酸诱导的神经分化过程中改变基因表达。总之，我们的结果证实了整合酶对转录组完整性的重要作用，并指出了整合酶复合物在人类大脑发育中的必要性。
