Institute for Protein Research, Graduate School of Science, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Genes Cells. 2011 Nov;16(11):1081-96. doi: 10.1111/j.1365-2443.2011.01554.x.
In budding yeast, Mps3 is essential for duplicating the spindle pole body (SPB) and is critical for promoting chromosome motion during meiosis. It is a member of the SUN (Sad1-Unc-84) domain family of proteins that localizes to the inner nuclear envelope (NE) in many eukaryotic organisms and preferentially localizes to the SPB in vegetative growth; in meiotic prophase I, it redistributes to many sites within the NE. We constructed an mps3 mutant, mps3-sun, which completely lacks the SUN domain. Surprisingly, the mps3-sun mutation does not disrupt SPB duplication or Mps3 localization to the NE in meiosis. However, it confers several defects during meiotic prophase I including reduced chromosome motion, premature synapsis between homologous chromosomes, and reduced levels of closely juxtaposed homologous loci in pachytene. These findings suggest that in meiosis, the Mps3 SUN domain is important for modulating chromosome motion events that act in meiotic chromosome juxtaposition and by extension, promoting proper morphogenesis of the synaptonemal complex.
在芽殖酵母中，Mps3 对于复制纺锤体极体（SPB）是必需的，并且对于促进有丝分裂过程中的染色体运动至关重要。它是 SUN（Sad1-Unc-84）结构域家族蛋白的成员，在许多真核生物中定位于核内 膜（NE），并在营养生长中优先定位于 SPB；在减数分裂前期 I 中，它重新分布到 NE 内的许多部位。我们构建了一个 mps3-sun 突变体，它完全缺乏 SUN 结构域。令人惊讶的是，mps3-sun 突变不会破坏 SPB 复制或 Mps3 在减数分裂中的 NE 定位。然而，它在减数分裂前期 I 中赋予了几个缺陷，包括染色体运动减少、同源染色体之间的早熟联会以及在粗线期紧密相邻的同源位点水平降低。这些发现表明，在减数分裂中，Mps3 SUN 结构域对于调节染色体运动事件很重要，这些事件作用于减数分裂染色体并列，并由此促进联会复合体的正确形态发生。
