State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
Genes (Basel). 2020 Feb 21;11(2):229. doi: 10.3390/genes11020229.
Ubiquitination is one of several post-transcriptional modifications of histone 2B (H2B) which affect the chromatin structure and, hence, influence gene transcription. This study focuses on a fungal pathogen responsible for leaf spot in many plant species. The experiments show that the product of a gene which encodes H2B monoubiquitination E3 ligase, regulates hyphal growth, conidial formation and pathogenicity. Knockout of by the homologous recombination strategy leads to the loss of H2B monoubiquitination (H2Bub1), as well as a remarkable decrease in the enrichment of trimethylated lysine 4 on histone 3 (H3K4me3). RNA sequencing assays elucidated that the transcription of genes encoding certain C2H2 zinc-finger family transcription factors, cell wall-degrading enzymes and chitin-binding proteins was suppressed in the knockout cells. GO enrichment analysis showed that these proteins encoded by the set of genes differentially transcribed between the deletion mutant and wild type were enriched in the functional categories "macramolecular complex", "cellular metabolic process", etc. A major conclusion was that the product, through its effect on histone 2B monoubiquitination and histone 3 lysine 4 trimethylation, makes an important contribution to the fungus's hyphal growth, conidial formation and pathogenicity.
泛素化是组蛋白 2B（H2B）的几种转录后修饰之一，它影响染色质结构，从而影响基因转录。本研究聚焦于一种真菌病原体，该病原体可导致许多植物物种的叶斑病。实验表明，编码 H2B 单泛素化 E3 连接酶的基因产物调节菌丝生长、分生孢子形成和致病性。通过同源重组策略敲除导致 H2B 单泛素化（H2Bub1）的丧失，以及组蛋白 3 上赖氨酸 4 三甲基化（H3K4me3）的丰度显著降低。RNA 测序分析表明，编码某些 C2H2 锌指家族转录因子、细胞壁降解酶和几丁质结合蛋白的基因的转录在Δ 缺失突变体细胞中受到抑制。GO 富集分析表明，在缺失突变体和野生型之间转录差异的一组基因编码的这些蛋白质富集在“大分子复合物”、“细胞代谢过程”等功能类别中。一个主要结论是，该基因产物通过影响组蛋白 2B 单泛素化和组蛋白 3 赖氨酸 4 三甲基化，对真菌的菌丝生长、分生孢子形成和致病性做出了重要贡献。
