Hoyt M A, He L, Loo K K, Saunders W S
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218.
J Cell Biol. 1992 Jul;118(1):109-20. doi: 10.1083/jcb.118.1.109.
Two Saccharomyces cerevisiae genes, CIN8 and KIP1 (a.k.a. CIN9), were identified by their requirement for normal chromosome segregation. Both genes encode polypeptides related to the heavy chain of the microtubule-based force-generating enzyme kinesin. Cin8p was found to be required for pole separation during mitotic spindle assembly at 37 degrees C, although overproduced Kip1p could substitute. At lower temperatures, the activity of at least one of these proteins was required for cell viability, indicating that they perform an essential but redundant function. Cin8p was observed to be a component of the mitotic spindle, colocalizing with the microtubules that lie between the poles. Taken together, these findings suggest that these proteins interact with spindle microtubules to produce an outwardly directed force acting upon the poles.
通过对正常染色体分离的需求，鉴定出了酿酒酵母的两个基因CIN8和KIP1（又称CIN9）。这两个基因都编码与基于微管的产生力的酶驱动蛋白重链相关的多肽。尽管过量产生的Kip1p可以替代，但发现Cin8p是37摄氏度下有丝分裂纺锤体组装过程中两极分离所必需的。在较低温度下，这些蛋白质中至少一种的活性是细胞存活所必需的，这表明它们执行着重要但冗余的功能。观察到Cin8p是有丝分裂纺锤体的一个组成部分，与两极之间的微管共定位。综上所述，这些发现表明这些蛋白质与纺锤体微管相互作用，产生作用于两极的向外定向力。
