Yoder Tennessee J, Pearson Chad G, Bloom Kerry, Davis Trisha N
Program in Molecular and Cellular Biology, University of Washington, Seattle, Washington 98195, USA.
Mol Biol Cell. 2003 Aug;14(8):3494-505. doi: 10.1091/mbc.e02-10-0655. Epub 2003 May 3.
During spindle pole body (SPB) duplication, the new SPB is assembled at a distinct site adjacent to the old SPB. Using quantitative fluorescence methods, we studied the assembly and dynamics of the core structural SPB component Spc110p. The SPB core exhibits both exchange and growth in a cell cycle-dependent manner. During G1/S phase, the old SPB exchanges approximately 50% of old Spc110p for new Spc110p. In G2 little Spc110p is exchangeable. Thus, Spc110p is dynamic during G1/S and becomes stable during G2. The SPB incorporates additional Spc110p in late G2 and M phases; this growth is followed by reduction in the next G1. Spc110p addition to the SPBs (growth) also occurs in response to G2 and mitotic arrests but not during a G1 arrest. Our results reveal several dynamic features of the SPB core: cell cycle-dependent growth and reduction, growth in response to cell cycle arrests, and exchange of Spc110p during SPB duplication. Moreover, rather than being considered a conservative or dispersive process, the assembly of Spc110p into the SPB is more readily considered in terms of growth and exchange.
在纺锤极体（SPB）复制过程中，新的SPB在与旧SPB相邻的一个不同位点组装。我们使用定量荧光方法研究了核心结构SPB组件Spc110p的组装和动态变化。SPB核心以细胞周期依赖性方式表现出交换和生长。在G1/S期，旧的SPB用大约50%的旧Spc110p交换新的Spc110p。在G2期，几乎没有可交换的Spc110p。因此，Spc110p在G1/S期是动态的，在G2期变得稳定。SPB在G2晚期和M期纳入额外的Spc110p；这种生长在接下来的G1期会随之减少。SPB添加Spc110p（生长）也会在G2期和有丝分裂停滞时发生，但在G1期停滞时不会发生。我们的结果揭示了SPB核心的几个动态特征：细胞周期依赖性生长和减少、对细胞周期停滞的生长反应以及SPB复制过程中Spc110p的交换。此外，Spc110p组装到SPB中与其说是一个保守或分散的过程，不如说是一个更容易从生长和交换的角度来考虑的过程。
