Li Y Y, Yeh E, Hays T, Bloom K
Department of Biology, University of North Carolina at Chapel Hill 27599-3280.
Proc Natl Acad Sci U S A. 1993 Nov 1;90(21):10096-100. doi: 10.1073/pnas.90.21.10096.
Dynein motor isoforms have been implicated as potential kinetochore-associated motors that power chromosome-to-pole movements during mitosis. The recent identification and sequence determination of genes encoding dynein isoforms has now permitted the in vivo analysis of dynein function in mitosis. In this report we describe the identification and mutational analysis of the gene, DHC1, encoding a dynein heavy chain isoform in Saccharomyces cerevisiae. Sequence analysis of a 9-kb genomic fragment of the DHC1 gene predicts a polypeptide highly homologous to dynein sequences characterized from sea urchin, Dictyostelium, Drosophila, and rat. Mutations in the yeast dynein gene disrupt the normal movement of the spindle into budding daughter cells but have no apparent effect on spindle assembly, spindle elongation, or chromosome segregation. Our results suggest that, in yeast, a dynein microtubule motor protein has a nonessential role in spindle assembly and chromosome movement but is involved in establishing the proper spindle orientation during cell division.
动力蛋白异构体被认为是潜在的与动粒相关的马达蛋白，在有丝分裂期间为染色体向两极的移动提供动力。最近对编码动力蛋白异构体的基因的鉴定和序列测定，使得对有丝分裂中动力蛋白功能的体内分析成为可能。在本报告中，我们描述了酿酒酵母中编码动力蛋白重链异构体的基因DHC1的鉴定和突变分析。对DHC1基因9 kb基因组片段的序列分析预测，其编码的多肽与海胆、盘基网柄菌、果蝇和大鼠中已鉴定的动力蛋白序列高度同源。酵母动力蛋白基因的突变会破坏纺锤体向出芽子细胞的正常移动，但对纺锤体组装、纺锤体延长或染色体分离没有明显影响。我们的结果表明，在酵母中，动力蛋白微管马达蛋白在纺锤体组装和染色体移动中起非必需作用，但参与细胞分裂过程中纺锤体的正确定向。
