The novel role of hnRNP UL1 in human cell nucleoli. The novel role of hnRNP UL1 in human cell nucleoli

hnRNPUL1 plays an important role in the cell nuclei, where it is recruited to DNA damage sites and is involved in the repair of DNA double-strand breaks. Furthermore, this protein is known as a transcriptional repressor of RNA polymerase II genes. In the present study, we have shown that hnRNP UL1 is also localized in the nucleoli. Revealing its function, we figured out that hnRNP UL1 stimulates ribosomal DNA (rDNA) gene transcription. We have performed high-throughput sequencing of libraries prepared from nucleolar and cytoplasmic-nuclear RNA fractions to identify differentially expressed ribosomal RNAs in wild-type and HNRNPUL1 knockout HEK293T cells. Overall design: We performed Nucleolar (NO) and Nuclear-Cytoplasmic (CN) fractionation of HEK293T wild-type and hnRNPUL1 knockout cells. The fractionated RNA was used to prepare libraries with biological triplicates from NO and CN RNA fractions from wild-type and HNRNPUL1KO cells.

异质性核核糖核蛋白UL1（hnRNPUL1）在细胞核内发挥关键功能，可被招募至DNA损伤位点，并参与DNA双链断裂的修复过程。此外，该蛋白被证实为RNA聚合酶II基因的转录抑制因子。本研究中，我们证实异质性核核糖核蛋白UL1同时定位于核仁。为解析其生物学功能，我们发现该蛋白可促进核糖体DNA（rDNA）基因的转录。我们针对野生型与HNRNPUL1基因敲除HEK293T细胞的核仁组分及胞质-核组分制备的RNA文库开展高通量测序，以鉴定差异表达的核糖体RNA。实验设计概述：我们对野生型及hnRNPUL1基因敲除HEK293T细胞进行了核仁（NO）与胞质-核（CN）组分分离，分离得到的RNA被用于构建文库，野生型与HNRNPUL1KO细胞的核仁、胞质-核RNA组分均设置3次生物学重复。