Ji Jianhui, Tang Ding, Shen Yi, Xue Zhihui, Wang Hongjun, Shi Wenqing, Zhang Chao, Du Guijie, Li Yafei, Cheng Zhukuan
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; Jiangsu Key Laboratory for Eco-Agriculture Biotechnology around Hongze Lake, Huaiyin Normal University, Huaian 223300, China.
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China;
Proc Natl Acad Sci U S A. 2016 Sep 20;113(38):10577-82. doi: 10.1073/pnas.1607334113. Epub 2016 Sep 6.
The human mitotic arrest-deficient 2 (Mad2) binding protein p31(comet) participates in the spindle checkpoint and coordinates cell cycle events in mitosis although its function in meiosis remains unknown in all organisms. Here, we reveal P31(comet) as a synaptonemal complex (SC) protein in rice (Oryza sativa L.). In p31(comet), homologous pairing and synapsis are eliminated, leading to the homologous nondisjunction and complete sterility. The failure in loading of histone H2AX phosphorylation (γH2AX) in p31(comet), together with the suppressed chromosome fragmentation in rice completion of meiotic recombination 1 (com1) p31(comet) and radiation sensitive 51c (rad51c) p31(comet) double mutants, indicates that P31(comet) plays an essential role in double-strand break (DSB) formation. Interestingly, the dynamic colocalization pattern between P31(comet) and ZEP1 (a transverse filament protein of SC) by immunostaining, as well as the interaction between P31(comet) and CENTRAL REGION COMPONENT 1 (CRC1) in yeast two-hybrid assays, suggests possible involvement of P31(comet) in SC installation. Together, these data indicate that P31(comet) plays a key role in DSB formation and SC installation, mainly through its cooperation with CRC1.
人类有丝分裂阻滞缺陷蛋白2（Mad2）结合蛋白p31（彗星）参与纺锤体检查点并协调有丝分裂中的细胞周期事件，尽管其在减数分裂中的功能在所有生物体中仍不清楚。在这里，我们揭示了水稻（Oryza sativa L.）中的联会复合体（SC）蛋白P31（彗星）。在p31（彗星）中，同源配对和联会被消除，导致同源染色体不分离和完全不育。p31（彗星）中组蛋白H2AX磷酸化（γH2AX）加载失败，以及水稻减数分裂重组完成1（com1）p31（彗星）和辐射敏感51c（rad51c）p31（彗星）双突变体中染色体片段化受到抑制，表明P31（彗星）在双链断裂（DSB）形成中起重要作用。有趣的是，通过免疫染色观察到P31（彗星）与ZEP1（SC的横向丝状蛋白）之间的动态共定位模式，以及酵母双杂交实验中P31（彗星）与中央区域成分1（CRC1）之间的相互作用，表明P31（彗星）可能参与SC组装。总之，这些数据表明P31（彗星）在DSB形成和SC组装中起关键作用，主要是通过与CRC1的合作。
