A Functional Link Between Bir1 and the Saccharomyces cerevisiae Ctf19 Kinetochore Complex Revealed Through Quantitative Fitness Analysis.
A Functional Link Between Bir1 and the Saccharomyces cerevisiae Ctf19 Kinetochore Complex Revealed Through Quantitative Fitness Analysis.
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DOI：
10.1534/g3.117.300089
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发表时间：
2017-09-07
期刊：
影响因子：
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通讯作者：
Stark MJR
中科院分区：
文献类型：
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作者：
Makrantoni V;Ciesiolka A;Lawless C;Fernius J;Marston A;Lydall D;Stark MJR
染色体乘客复合体（CPC）是真核细胞分裂的关键调节因子，由蛋白激酶Aurora B/Ipl1及其激活因子（INCENP/Sli15）和两个附加蛋白（Survivin/Bir1和Borealin/Nbl1）组成。在这里，我们使用bir1-17突变体在酿酒酵母中进行了全基因组遗传相互作用筛选，通过定量适应度分析确定了作为增强子和抑制子的缺失突变。影响Ctf19着丝粒复合物的基因敲除被确定为bir1-17的最强增强子，而影响大核糖体亚基或mRNA无义介导的衰变途径的突变引起强烈的表型抑制。因此，缺乏功能性Ctf19复合物的细胞变得高度依赖Bir1功能，反之亦然。bir1-17和内聚蛋白突变体mcd1-1的负相互作用谱显示出相当大的重叠，这表明姐妹染色单体内聚和染色体双向性之间存在很强的功能联系。与其他CPC成分的突变相比，某些Ctf19成分（如Iml3或Chl4）的缺失对bir1-17的影响是不同的：尽管Iml3∆或Chl4∆与bir1-17联合表现出合成致死率，但基因敲除均未显示与ipl1-321或sli15-3有任何遗传相互作用。因此，我们的数据暗示Ctf19复合物和Bir1之间存在与Ipl1不共享的特定功能连接。
The chromosomal passenger complex (CPC) is a key regulator of eukaryotic cell division, consisting of the protein kinase Aurora B/Ipl1 in association with its activator (INCENP/Sli15) and two additional proteins (Survivin/Bir1 and Borealin/Nbl1). Here, we report a genome-wide genetic interaction screen in Saccharomyces cerevisiae using the bir1-17 mutant, identifying through quantitative fitness analysis deletion mutations that act as enhancers and suppressors. Gene knockouts affecting the Ctf19 kinetochore complex were identified as the strongest enhancers of bir1-17, while mutations affecting the large ribosomal subunit or the mRNA nonsense-mediated decay pathway caused strong phenotypic suppression. Thus, cells lacking a functional Ctf19 complex become highly dependent on Bir1 function and vice versa. The negative genetic interaction profiles of bir1-17 and the cohesin mutant mcd1-1 showed considerable overlap, underlining the strong functional connection between sister chromatid cohesion and chromosome biorientation. Loss of some Ctf19 components, such as Iml3 or Chl4, impacted differentially on bir1-17 compared with mutations affecting other CPC components: despite the synthetic lethality shown by either iml3∆ or chl4∆ in combination with bir1-17, neither gene knockout showed any genetic interaction with either ipl1-321 or sli15-3. Our data therefore imply a specific functional connection between the Ctf19 complex and Bir1 that is not shared with Ipl1.