Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, United States.
Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, United States.
Elife. 2019 Jan 18;8:e40372. doi: 10.7554/eLife.40372.
The meiotic chromosome axis plays key roles in meiotic chromosome organization and recombination, yet the underlying protein components of this structure are highly diverged. Here, we show that 'axis core proteins' from budding yeast (Red1), mammals (SYCP2/SYCP3), and plants (ASY3/ASY4) are evolutionarily related and play equivalent roles in chromosome axis assembly. We first identify 'closure motifs' in each complex that recruit meiotic HORMADs, the master regulators of meiotic recombination. We next find that axis core proteins form homotetrameric (Red1) or heterotetrameric (SYCP2:SYCP3 and ASY3:ASY4) coiled-coil assemblies that further oligomerize into micron-length filaments. Thus, the meiotic chromosome axis core in fungi, mammals, and plants shares a common molecular architecture, and likely also plays conserved roles in meiotic chromosome axis assembly and recombination control.
减数分裂染色体轴在减数分裂染色体组织和重组中发挥着关键作用，但该结构的潜在蛋白质成分高度多样化。在这里，我们表明来自酿酒酵母（Red1）、哺乳动物（SYCP2/SYCP3）和植物（ASY3/ASY4）的“轴核心蛋白”在染色体轴组装中具有进化关系并发挥等效作用。我们首先在每个复合物中鉴定出“封闭基序”，这些基序招募减数分裂 HORMADs，这是减数分裂重组的主要调节剂。接下来，我们发现轴核心蛋白形成同源四聚体（Red1）或异源四聚体（SYCP2:SYCP3 和 ASY3:ASY4）的螺旋卷曲组装体，进一步寡聚形成微米长度的细丝。因此，真菌、哺乳动物和植物的减数分裂染色体轴核心具有共同的分子结构，并且可能在减数分裂染色体轴组装和重组控制中也发挥保守作用。
