ANALYSIS OF CHROMOSOMESEGREGATION MECHANISM BY HUMAN CH-TOG RELATED GENES IN YEAST

分裂酵母S. pombe非1突变体在姐妹染色单体分离中存在缺陷。Dis1属于一个进化保守的微管结合蛋白家族，包括人类的ch-TOG、青蛙的XMAP215、苍蝇的微管和出芽酵母的Stu2p。我们发现Dis1-GFP信号与细胞质微管、纺锤体微管和纺锤体极体有关。令人惊讶的是，当细胞在有丝分裂过程中从中期进入后期时，Dis1-GFP信号与着丝点蛋白如Mis6、Mis12的信号相似。Dis1是第一个与微管和着丝点的着丝粒DNA结合的裂变酵母蛋白。Dis1可能通过以m期特定方式成为着丝点的一部分发挥双重作用，可能在着丝点和微管之间产生连接。我们还表明，与Dis1高度相关的蛋白质，称为Mtc1/Alp14，其行为方式与Dis1相似，但不完全相同。它们的行为表明这两种相关分子在与微管相互作用方面存在显著差异。

Fission yeast S. pombe dis1 mutants are defective in sister chromatids separation. Dis1 belongs to an evolutionarily conserved family of microtubule binding proteins, including human ch-TOG, frog XMAP215, fly minispindles and budding yeast Stu2p. We found Dis1-GFP signals are associated with cytoplasmic microtubules, spindle microtubules and spindle pole bodies. Surprisingly, as cells progress from metaphase to anaphase during mitosis, Dis1-GFP signals mimic those of kinetochore proteins such as Mis6, Mis12. Dis1 is the first fission yeast protein that associates with both microtubules and the centromeric DNA of the kinetochore. Dis1 may play a dual role by becoming a part of the kinetochores in an M-phase specific manner, possibly generating connections between kinetochores and microtubules.We have also shown that protein highly related to Dis1, called Mtc1/Alp14, behaves in a similar but not identical manner to Dis1. Their behavior suggests that these two related molecules have significant differences in interaction with microtubules.