Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
Nucleic Acids Res. 2020 Nov 4;48(19):10848-10866. doi: 10.1093/nar/gkaa815.
Centromeres are genomic regions essential for faithful chromosome segregation. Transcription of noncoding RNA (ncRNA) at centromeres is important for their formation and functions. Here, we report the molecular mechanism by which the transcriptional regulator ZFAT controls the centromeric ncRNA transcription in human and mouse cells. Chromatin immunoprecipitation with high-throughput sequencing analysis shows that ZFAT binds to centromere regions at every chromosome. We find a specific 8-bp DNA sequence for the ZFAT-binding motif that is highly conserved and widely distributed at whole centromere regions of every chromosome. Overexpression of ZFAT increases the centromeric ncRNA levels at specific chromosomes, whereas its silencing reduces them, indicating crucial roles of ZFAT in centromeric transcription. Overexpression of ZFAT increases the centromeric levels of both the histone acetyltransferase KAT2B and the acetylation at the lysine 8 in histone H4 (H4K8ac). siRNA-mediated knockdown of KAT2B inhibits the overexpressed ZFAT-induced increase in centromeric H4K8ac levels, suggesting that ZFAT recruits KAT2B to centromeres to induce H4K8ac. Furthermore, overexpressed ZFAT recruits the bromodomain-containing protein BRD4 to centromeres through KAT2B-mediated H4K8ac, leading to RNA polymerase II-dependent ncRNA transcription. Thus, ZFAT binds to centromeres to control ncRNA transcription through the KAT2B-H4K8ac-BRD4 axis.
着丝粒是保证染色体正确分离的基因组区域。着丝粒处非编码 RNA(ncRNA)的转录对于其形成和功能至关重要。在这里,我们报告了转录调节因子 ZFAT 控制人类和小鼠细胞着丝粒 ncRNA 转录的分子机制。高吞吐量测序的染色质免疫沉淀分析表明,ZFAT 结合到每条染色体的着丝粒区域。我们发现了一个特定的 8 个碱基对 DNA 序列,是 ZFAT 结合基序,在每条染色体的整个着丝粒区域高度保守且广泛分布。ZFAT 的过表达增加了特定染色体上的着丝粒 ncRNA 水平,而其沉默则降低了它们,表明 ZFAT 在着丝粒转录中起着关键作用。ZFAT 的过表达增加了组蛋白乙酰转移酶 KAT2B 和组蛋白 H4 赖氨酸 8 乙酰化(H4K8ac)的着丝粒水平。siRNA 介导的 KAT2B 敲低抑制了过表达 ZFAT 诱导的着丝粒 H4K8ac 水平增加,表明 ZFAT 将 KAT2B 募集到着丝粒以诱导 H4K8ac。此外,过表达的 ZFAT 通过 KAT2B 介导的 H4K8ac 将包含溴结构域的蛋白 BRD4 募集到着丝粒,导致 RNA 聚合酶 II 依赖性 ncRNA 转录。因此,ZFAT 通过 KAT2B-H4K8ac-BRD4 轴结合到着丝粒来控制 ncRNA 转录。