Hatsumi M, Endow S A
Department of Microbiology, Duke University Medical Center, Durham, North Carolina 27710.
J Cell Sci. 1992 Dec;103 ( Pt 4):1013-20. doi: 10.1242/jcs.103.4.1013.
The nonclaret disjunctional (ncd) protein is required for normal chromosome distribution in oocytes and early embryos. Mutants of ncd cause frequent nondisjunction and loss of chromosomes, suggesting a role for the protein in spindle function or chromosome movement in meiosis and early mitosis. The ncd protein contains a region of predicted sequence similarity to the microtubule motor protein, kinesin. In vitro motility assays have demonstrated that ncd is a motor that unexpectedly moves toward the minus ends of microtubules, opposite to the direction of kinesin movement. Using antibodies directed against nonconserved regions of the protein, we have localized the ncd motor protein to the meiotic and early mitotic spindle, and to spindles in a mitotically dividing cultured cell line. Its presence in the spindle of meiotic and mitotic cells implies a role for the protein as a spindle motor. The motor may play an essential role in establishing spindle bipolarity in meiosis.
非红葡萄酒不分离（ncd）蛋白是卵母细胞和早期胚胎中正常染色体分布所必需的。ncd突变体导致频繁的不分离和染色体丢失，表明该蛋白在减数分裂和早期有丝分裂中的纺锤体功能或染色体运动中发挥作用。ncd蛋白包含一个与微管运动蛋白驱动蛋白预测序列相似的区域。体外运动分析表明，ncd是一种马达蛋白，意外地朝着微管的负端移动，与驱动蛋白的移动方向相反。利用针对该蛋白非保守区域的抗体，我们已将ncd马达蛋白定位到减数分裂和早期有丝分裂纺锤体以及有丝分裂分裂的培养细胞系中的纺锤体上。它在减数分裂和有丝分裂细胞纺锤体中的存在意味着该蛋白作为纺锤体马达发挥作用。该马达蛋白可能在减数分裂中建立纺锤体双极性方面发挥重要作用。
