Rad6-Bre1-mediated histone H2B ubiquitylation modulates the formation of double-strand breaks during meiosis.
Rad6-Bre1-mediated histone H2B ubiquitylation modulates the formation of double-strand breaks during meiosis.
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DOI：
10.1073/pnas.0400078101
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发表时间：
2004-08
影响因子：
11.1
通讯作者：
K. Yamashita;M. Shinohara;A. Shinohara
中科院分区：
文献类型：
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作者：
K. Yamashita;M. Shinohara;A. Shinohara
E2 泛素结合酶 Rad6 与 E3 泛素连接酶 Bre1 一起作用，催化组蛋白 H2B 在 C 端赖氨酸残基上的单泛素化。酿酒酵母的 rad6 突变体显示减数分裂前期停滞。在这里，我们分析了芽殖酵母 rad6 null 突变体的减数分裂缺陷。 rad6突变体在减数分裂过程中表现出多效性表型。 RAD6 是减数分裂重组热点处有效形成双链断裂 (DSB) 所必需的，由 Spo11 催化。该突变降低了细胞中 DSB 的总体频率。 rad6 突变的影响是沿染色体局部的；在突变体中，较强热点处的 DSB 水平尤其降低。 RAD6 的缺失对带有 Gal4 DNA 结合域的 Spo11 融合蛋白靶向的异位 DSB 的形成几乎没有影响。此外，BRE1 的破坏以及组蛋白 H2B 泛素化位点的取代也减少了一些类似于 rad6 的 DSB 形成。这些结果表明，Rad6-Bre1 通过组蛋白 H2B 的泛素化，对于有效招募和/或稳定包含 Spo11 的 DSB 形成机制是必需的。组蛋白尾部修饰可能在减数分裂过程中 DSB 的形成中发挥作用。
An E2 ubiquitin-conjugating enzyme, Rad6, working with an E3 ubiquitin ligase Bre1, catalyzes monoubiquitylation of histone H2B on a C-terminal lysine residue. The rad6 mutant of Saccharomyces cerevisiae shows a meiotic prophase arrest. Here, we analyzed meiotic defects of a rad6 null mutant of budding yeast. The rad6 mutant exhibits pleiotropic phenotypes during meiosis. RAD6 is required for efficient formation of double-strand breaks (DSBs) at meiotic recombination hotspots, which is catalyzed by Spo11. The mutation decreases overall frequencies of DSBs in a cell. The effect of the rad6 mutation is local along chromosomes; levels of DSBs at stronger hotspots are particularly reduced in the mutant. The absence of RAD6 has little effect on the formation of ectopic DSBs targeted by Spo11 fusion protein with a Gal4 DNA-binding domain. Furthermore, the disruption of the BRE1 as well as substitution of the ubiquitylation site of histone H2B also reduces some DSB formation similar to the rad6. These results suggest that Rad6-Bre1, through ubiquitylation of histone H2B, is necessary for efficient recruitment and/or stabilization of a DSB-forming machinery containing Spo11. Histone tail modifications might play a role in DSB formation during meiosis.