酵母着丝粒结合蛋白复合体的微管运动活性

Microtubule-motor activity of a yeast centromere-binding protein complex.

作者信息

Hyman A A, Middleton K, Centola M, Mitchison T J, Carbon J

机构信息

Department of Pharmacology, University of California, San Francisco 94143.

出版信息

Nature. 1992 Oct 8;359(6395):533-6. doi: 10.1038/359533a0.

DOI:10.1038/359533a0

PMID:1406970

Abstract

During cell division, sister chromosomes segregate from each other on a microtubule-based structure called the mitotic spindle. Proteins bind to the centromere, a region of chromosomal DNA, to form the kinetochore, which mediates chromosome attachment to the mitotic spindle microtubules. In the budding yeast Saccharomyces cerevisiae, genetic analysis has shown that the 28-basepair (bp) CDEIII region of the 125-bp centromere DNA sequence (CEN sequence) is the main region controlling chromosome segregation in vivo. Therefore it is likely that proteins binding to the CDEIII region link the centromeres to the microtubules during mitosis. A complex of proteins (CBF3) that binds specifically to the CDEIII DNA sequence has been isolated by affinity chromatography. Here we describe kinetochore function in vitro. The CBF3 complex can link DNA to microtubules, and the complex contains a minus-end-directed microtubule-based motor. We suggest that microtubule-based motors form the fundamental link between microtubules and chromosomes at mitosis.

摘要

在细胞分裂过程中，姐妹染色体在一种称为有丝分裂纺锤体的基于微管的结构上彼此分离。蛋白质与染色体DNA区域着丝粒结合，形成动粒，动粒介导染色体与有丝分裂纺锤体微管的附着。在出芽酵母酿酒酵母中，遗传分析表明，125碱基对（bp）着丝粒DNA序列（CEN序列）的28碱基对（bp）CDEIII区域是体内控制染色体分离的主要区域。因此，在有丝分裂期间，与CDEIII区域结合的蛋白质可能将着丝粒与微管连接起来。通过亲和层析分离出了一种与CDEIII DNA序列特异性结合的蛋白质复合物（CBF3）。在此我们描述了体外动粒的功能。CBF3复合物可以将DNA与微管连接起来，并且该复合物包含一种基于微管的负端定向马达蛋白。我们认为，基于微管的马达蛋白在有丝分裂时形成了微管与染色体之间的基本连接。