Systematic yeast synthetic lethal and synthetic dosage lethal screens identify genes required for chromosome segregation
Systematic yeast synthetic lethal and synthetic dosage lethal screens identify genes required for chromosome segregation
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DOI：
10.1073/pnas.0503504102
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发表时间：
2005-09-27
影响因子：
11.1
通讯作者：
Andrews, B
中科院分区：
文献类型：
--
作者：
Measday, V;Baetz, K;Andrews, B
准确的染色体分离要求有丝分裂过程中许多过程的执行和协调，包括DNA复制、姐妹染色单体凝聚以及染色体通过着丝粒复合体附着到纺锤体微管上。可能还涉及到其他途径，因为忠实的染色体分离还需要与染色体没有物理联系的蛋白质。以着丝粒突变体为起点，我们通过使用合成基因阵列方法进行全基因组筛选，确定了与染色体稳定性有关的基因。两种遗传方法(一系列合成致死和合成剂量致死筛选)分离出211个不能耐受动粒功能缺陷的非必要缺失突变体。虽然合成致死性和合成剂量致死性被认为是基于相似的遗传原理，但我们发现与这两个屏幕相关的大多数相互作用是不重叠的。为了从功能上鉴定在我们的筛查中分离的基因，进行了二次筛查以评估染色体分离中的缺陷。在二次筛查中发现的基因丰富了已知在染色体分离中的作用的基因。我们还发现了具有不同功能的基因，例如编码铁转录因子的RCS1。RCS1是在所有三个筛查中发现的一小部分基因之一，我们使用遗传和细胞生物学分析来确认它是染色体稳定所必需的。我们的研究表明，系统的遗传筛选是发现未知基因和具有替代功能的基因在染色体维持中的作用的有力手段，而这些作用可能是用蛋白质组学方法无法发现的。
Accurate chromosome segregation requires the execution and coordination of many processes during mitosis, including DNA replication, sister chromatid cohesion, and attachment of chromosomes to spindle microtubules via the kinetochore complex. Additional pathways are likely involved because faithful chromosome segregation also requires proteins that are not physically associated with the chromosome. Using kinetochore mutants as a starting point, we have identified genes with roles in chromosome stability by performing genome-wide screens employing synthetic genetic array methodology. Two genetic approaches (a series of synthetic lethal and synthetic dosage lethal screens) isolated 211 nonessential deletion mutants that were unable to tolerate defects in kinetochore function. Although synthetic lethality and synthetic dosage lethality are thought to be based upon similar genetic principles, we found that the majority of interactions associated with these two screens were nonoverlapping. To functionally characterize genes isolated in our screens, a secondary screen was performed to assess defects in chromosome segregation. Genes identified in the secondary screen were enriched for genes with known roles in chromosome segregation. We also uncovered genes with diverse functions, such as RCS1, which encodes an iron transcription factor. RCS1 was one of a small group of genes identified in all three screens, and we used genetic and cell biological assays to confirm that it is required for chromosome stability. Our study shows that systematic genetic screens are a powerful means to discover roles for uncharacterized genes and genes with alternative functions in chromosome maintenance that may not be discovered by using proteornics approaches.