Department of Biology, McGill University, 1205 avenue Docteur Penfield, Montreal, Quebec H2A 1B1, Canada.
Dev Cell. 2011 Nov 15;21(5):948-58. doi: 10.1016/j.devcel.2011.07.011. Epub 2011 Oct 20.
During meiosis, chromosomes must find and align with their homologous partners. SUN and KASH-domain protein pairs play a conserved role by establishing transient linkages between chromosome ends and cytoskeletal forces across the intact nuclear envelope (NE). In C. elegans, a pairing center (PC) on each chromosome mediates homolog pairing and linkage to the microtubule network. We report that the polo kinases PLK-1 and PLK-2 are targeted to the PC by ZIM/HIM-8-pairing proteins. Loss of plk-2 inhibits chromosome pairing and licenses synapsis between nonhomologous chromosomes, indicating that PLK-2 is required for PC-mediated interhomolog interactions. plk-2 is also required for meiosis-specific phosphorylation of SUN-1 and establishment of dynamic SUN/KASH (SUN-1/ZYG-12) modules that promote homolog pairing. Our results provide key insights into the regulation of homolog pairing and reveal that targeting of polo-like kinases to the NE by meiotic chromosomes establishes the conserved linkages to cytoskeletal forces needed for homology assessment.
在减数分裂过程中,染色体必须找到并与同源伴侣对齐。SUN 和 KASH 结构域蛋白对通过在完整核膜 (NE) 上建立染色体末端和细胞骨架力之间的瞬时连接,发挥保守作用。在秀丽隐杆线虫中,每个染色体上的配对中心 (PC) 介导同源物配对和与微管网络的连接。我们报告说,极激酶 PLK-1 和 PLK-2 被 ZIM/HIM-8 配对蛋白靶向到 PC。plk-2 的缺失抑制染色体配对,并允许非同源染色体之间的联会,表明 PLK-2 是 PC 介导的交互同源物相互作用所必需的。plk-2 还需要 SUN-1 的减数特异性磷酸化和动态 SUN/KASH(SUN-1/ZYG-12)模块的建立,该模块促进同源物配对。我们的结果提供了同源物配对调控的关键见解,并表明通过减数分裂染色体将 Polo 样激酶靶向到 NE,建立了与同源性评估所需的细胞骨架力的保守连接。