He Yi, Wang Chong, Higgins James D, Yu Junping, Zong Jie, Lu Pingli, Zhang Dabing, Liang Wanqi
Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 20040, China.
Department of Genetics, University of Leicester, Leicester LE1 7RH, United Kingdom.
Plant Cell. 2016 Aug;28(8):1879-93. doi: 10.1105/tpc.16.00108. Epub 2016 Jul 19.
F-box proteins constitute a large superfamily in plants and play important roles in controlling many biological processes, but the roles of F-box proteins in male meiosis in plants remain unclear. Here, we identify the rice (Oryza sativa) F-box gene MEIOTIC F-BOX (MOF), which is essential for male meiotic progression. MOF belongs to the FBX subfamily and is predominantly active during leptotene to pachytene of prophase I. mof meiocytes display disrupted telomere bouquet formation, impaired pairing and synapsis of homologous chromosomes, and arrested meiocytes at late prophase I, followed by apoptosis. Although normal, programmed double-stranded DNA breaks (DSBs) form in mof mutants, foci of the phosphorylated histone variant γH2AX, a marker for DSBs, persist in the mutant, indicating that many of the DSBs remained unrepaired. The recruitment of Completion of meiosis I (COM1) and Radiation sensitive51C (RAD51C) to DSBs is severely compromised in mutant meiocytes, indicating that MOF is crucial for DSB end-processing and repair. Further analyses showed that MOF could physically interact with the rice SKP1-like Protein1 (OSK1), indicating that MOF functions as a component of the SCF E3 ligase to regulate meiotic progression in rice. Thus, this study reveals the essential role of an F-box protein in plant meiosis and provides helpful information for elucidating the roles of the ubiquitin proteasome system in plant meiotic progression.
F-box蛋白在植物中构成一个庞大的超家族，在控制许多生物学过程中发挥重要作用，但F-box蛋白在植物雄性减数分裂中的作用仍不清楚。在此，我们鉴定了水稻（Oryza sativa）F-box基因减数分裂F-box（MEIOTIC F-BOX，MOF），它对雄性减数分裂进程至关重要。MOF属于FBX亚家族，在减数第一次分裂前期的细线期到粗线期主要发挥作用。mof减数分裂细胞表现出端粒花束形成紊乱、同源染色体配对和联会受损，减数分裂细胞在减数第一次分裂前期后期停滞，随后发生凋亡。尽管在mof突变体中正常的程序性双链DNA断裂（DSBs）形成，但DSBs的标志物磷酸化组蛋白变体γH2AX的焦点在突变体中持续存在，表明许多DSBs仍未修复。减数分裂I完成蛋白（COM1）和辐射敏感蛋白51C（RAD51C）向DSBs的募集在突变体减数分裂细胞中严重受损，表明MOF对DSB末端处理和修复至关重要。进一步分析表明，MOF可与水稻SKP1样蛋白1（OSK1）发生物理相互作用，表明MOF作为SCF E3连接酶的一个组分发挥作用，以调控水稻减数分裂进程。因此，本研究揭示了一个F-box蛋白在植物减数分裂中的重要作用，并为阐明泛素蛋白酶体系统在植物减数分裂进程中的作用提供了有用信息。
