EVIDENCE THAT THE MIF2 GENE OF SACCHAROMYCES-CEREVISIAE ENCODES A CENTROMERE PROTEIN WITH HOMOLOGY TO THE MAMMALIAN CENTROMERE PROTEIN CENP-C
EVIDENCE THAT THE MIF2 GENE OF SACCHAROMYCES-CEREVISIAE ENCODES A CENTROMERE PROTEIN WITH HOMOLOGY TO THE MAMMALIAN CENTROMERE PROTEIN CENP-C
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DOI：
10.1091/mbc.6.7.793
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发表时间：
1995-07-01
影响因子：
3.3
通讯作者：
KOSHLAND, D
中科院分区：
文献类型：
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作者：
MELUH, PB;KOSHLAND, D
酿酒酵母的MIF2基因与有丝分裂有关。在这里，我们提供了遗传证据，证明MIF2编码着丝粒蛋白。具体来说，我们发现MIF2突变稳定了双中心小染色体，并赋予酵母着丝粒DNA （CDEI）元素I顺式作用突变的染色体高度不稳定性（即合成的无中心表型）。同样地，我们观察到MIF2突变和三个已知酵母着丝粒蛋白基因（cep1 /CBF1/CPF1、NDC10/CBF2和CEP3/CBF3B）的反式作用突变之间的合成表型。此外，增加CEP1的剂量可以部分恢复mif2的温度敏感表型。cep1空突变与NDC10或CEP3突变之间的合成致死相互作用也被检测到。综合来看，这些数据表明。Mif2蛋白在着丝粒上与Cep1p相互作用，酵母着丝粒确实以一种更高阶的蛋白质- dna复合物的形式存在。Mif2和Cep1蛋白含有已知转录因子的基序，这表明酵母着丝粒的组装类似于真核增强子的组装和复制的起源。我们还表明，预测的Mif2蛋白与哺乳动物着丝粒Ag CENP-C有两个短同源区域，并且Mif2的两个温度敏感突变位于这些区域内。这些结果为酵母和哺乳动物着丝粒之间的结构守恒提供了证据。
The MIF2 gene of Saccharomyces cerevisiae has been implicated in mitosis. Here we provide genetic evidence that MIF2 encodes a centromere protein. Specifically, we found that mutations in MIF2 stabilize dicentric minichromosomes and confer high instability (i.e., a synthetic acentric phenotype) to chromosomes that bear a cis-acting mutation in element I of the yeast centromeric DNA (CDEI). Similarly, we observed synthetic phenotypes between mutations in MIF2 and trans-acting mutations in three known yeast centromere protein genes-CEP1/CBF1/CPF1, NDC10/CBF2, and CEP3/CBF3B. In addition, the mif2 temperature-sensitive phenotype can be partially rescued by increased dosage of CEP1. Synthetic lethal interactions between a cep1 null mutation and mutations in either NDC10 or CEP3 were also detected. Taken together, these data suggest that the. Mif2 protein interacts with Cep1p at the centromere and that the yeast centromere indeed exists as a higher order protein-DNA complex. The Mif2 and Cep1 proteins contain motifs of known transcription factors, suggesting that assembly of the yeast centromere is analogous to that of eukaryotic enhancers and origins of replication. We also show that the predicted Mif2 protein shares two short regions of homology with the mammalian centromere Ag CENP-C and that two temperature-sensitive mutations in MIF2 lie within these regions. These results provide evidence for structural conservation between yeast and mammalian centromeres.