Zhao Xin-Xi, Zhang Yun-Bin, Ni Pei-Li, Wu Zhi-Li, Yan Yuan-Chang, Li Yi-Ping
From the State Key Laboratory of Cell Biology, Shanghai Key Laboratory for Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
From the State Key Laboratory of Cell Biology, Shanghai Key Laboratory for Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
J Biol Chem. 2016 Jan 1;291(1):402-12. doi: 10.1074/jbc.M115.666347. Epub 2015 Oct 20.
Histone lysine methylation is important in early zebrafish development; however, the role of histone arginine methylation in this process remains unclear. H3R2me2a, generated by protein arginine methyltransferase 6 (Prmt6), is a repressive mark. To explore the role of Prmt6 and H3R2me2a during zebrafish embryogenesis, we identified the maternal characteristic of prmt6 and designed two prmt6-specific morpholino-oligos (MOs) to study its importance in early development, application of which led to early epiboly defects and significantly reduced the level of H3R2me2a marks. prmt6 mRNA could rescue the epiboly defects and the H3R2me2a reduction in the prmt6 morphants. Functionally, microarray data demonstrated that growth arrest and DNA damage-inducible, α, a (gadd45αa) was a significantly up-regulated gene in MO-treated embryos, the activity of which was linked to the activation of the p38/JNK pathway and apoptosis. Importantly, gadd45αa MO and p38/JNK inhibitors could partially rescue the defect of prmt6 morphants, the downstream targets of Prmt6, and the apoptosis ratios of the prmt6 morphants. Moreover, the results of ChIP quantitative real time PCR and luciferase reporter assay indicated that gadd45αa is a repressive target of Prmt6. Taken together, these results suggest that maternal Prmt6 is essential to early zebrafish development by directly repressing gadd45αa.
组蛋白赖氨酸甲基化在斑马鱼早期发育中很重要；然而，组蛋白精氨酸甲基化在此过程中的作用仍不清楚。由蛋白质精氨酸甲基转移酶6（Prmt6）产生的H3R2me2a是一种抑制性标记。为了探究Prmt6和H3R2me2a在斑马鱼胚胎发生过程中的作用，我们鉴定了prmt6的母源特征，并设计了两种prmt6特异性吗啉代寡核苷酸（MOs）来研究其在早期发育中的重要性，使用这些MOs会导致早期外包缺陷，并显著降低H3R2me2a标记的水平。prmt6 mRNA可以挽救prmt6 morphants中的外包缺陷和H3R2me2a的减少。在功能上，微阵列数据表明，生长停滞和DNA损伤诱导蛋白α（gadd45αa）是MO处理胚胎中显著上调的基因，其活性与p38/JNK途径的激活和细胞凋亡有关。重要的是，gadd45αa MO和p38/JNK抑制剂可以部分挽救prmt6 morphants的缺陷、Prmt6的下游靶点以及prmt6 morphants的凋亡率。此外，染色质免疫沉淀定量实时PCR和荧光素酶报告基因检测结果表明，gadd45αa是Prmt6的一个抑制靶点。综上所述，这些结果表明母源Prmt6通过直接抑制gadd45αa对斑马鱼早期发育至关重要。
