Suppressor analysis of the mpt5/htr1/uth4/puf5 deletion in Saccharomyces cerevisiae
Suppressor analysis of the mpt5/htr1/uth4/puf5 deletion in Saccharomyces cerevisiae
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DOI：
10.1007/s00438-005-0064-x
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发表时间：
2006-01-01
影响因子：
3.1
通讯作者：
Kikuchi, A
中科院分区：
文献类型：
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作者：
Ohkuni, K;Kikuchi, Y;Kikuchi, A
在酿酒酵母中，MPT5/HTR1/UTH4/PUF5基因编码一个RNA结合的Puf家族蛋白。Delta mpt5细胞在高温下表现出多效性，包括细胞周期的G2/M期停滞和细胞壁的削弱。Delta mpt5干扰物也对羟基脲(HU)敏感。在本研究中，我们筛选了缺失抑制基因来挽救Delta mpt5的温度敏感性，并鉴定了dsf1(YEL070W)、dsf2(YBR007C)、sir2、sir3、sir4和Swe1。多拷贝抑制基因是PKC1及其上游基因，而不是下游的MAPK级联基因。然而，PKC1的过表达并不能抑制Delta mpt5的HU敏感性。相反，a型Delta mpt5细胞对HU和温度的敏感性都被每个SIR缺失或MATα2的多拷贝抑制，这表明参与了二倍体的表达。我们发现编码RNA修饰蛋白的二倍体特异性IME4基因负责抑制温度敏感性，而不是HU敏感性。此外，另一个PUF家族基因PUF4抑制HU敏感性，PUF4的过表达仅抑制Delta mpt5的HU敏感性。PUF4蛋白水平不受SIR突变的影响。因此，这些Ime4和Puf4蛋白在修复Delta mpt5 Delta SIR细胞中的缺陷方面发挥了互补的作用。
The MPT5/HTR1/UTH4/PUF5 gene encodes an RNA-binding Puf-family protein in Saccharomyces cerevisiae. The Delta mpt5 cells exhibit pleiotropic phenotypes, including the G2/M arrest of the cell cycle and weakened cell wall at high temperatures. The Delta mpt5 disruptant was also hydroxyurea (HU) sensitive. In this study we screened deletion suppressors to rescue the temperature sensitivity of Delta mpt5, and identified dsf1 (YEL070W), dsf2 (YBR007C), sir2, sir3, sir4 and swe1. Multicopy suppressors identified were PKC1 and its upstream genes, but not the downstream MAPK cascade genes. The overexpression of PKC1, however, did not suppress the HU sensitivity of Delta mpt5. In contrast, both the HU- and temperature-sensitivities of a-type Delta mpt5 cells were suppressed by each sir deletion or a multicopy of MAT alpha 2, suggesting that a diploid-type expression is involved. We found that a diploid-specific IME4 gene encoding an RNA-modifying protein was responsible for the suppression of the temperature sensitivity, but not of the HU sensitivity. Furthermore, the suppression of the HU sensitivity depended on PUF4, another Puf-family gene, and overexpression of PUF4 suppressed only the HU sensitivity of Delta mpt5. The protein level of Puf4 was not affected by the sir mutation. Thus, these Ime4 and Puf4 proteins play complementary roles to rescue the defects in Delta mpt5 Delta sir cells.