Masuda Ryo, Yoshikawa Munetaka, Moriuchi Ryota, Oba Yumiko, Dohra Hideo, Kimura Yoko
Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan.
Shizuoka Instrumental Analysis Center, Shizuoka University, Shizuoka 422-8529, Japan.
Cells. 2024 Dec 5;13(23):2011. doi: 10.3390/cells13232011.
To identify new ubiquitin-related functions using yeast, we searched for mutants conferring a temperature-sensitivity phenotype that could be rescued through ubiquitin overexpression. Screening of mutants using this overexpression strategy identified , which encodes a subunit of the endoplasmic reticulum (ER) signal peptidase complex (SPC). Ubiquitin overexpression rescued a high-temperature sensitivity of deletion mutant, suggesting that ubiquitin could compensate for Spc2 loss-of-function at high temperatures. The double mutant of Spc2 and Hrd1, an ER E3 ubiquitin ligase, showed a synergistic growth defect at higher temperatures. A weak genetic interaction was also observed between spc2Δ and mutation. The results suggest a close functional relationship between SPC and the ubiquitin-proteasome system in yeast and further provide proof-of-principle for this ubiquitin overexpression approach to identify novel ubiquitin-related genes and associated cellular processes.
为了利用酵母鉴定新的泛素相关功能，我们寻找了能赋予温度敏感表型且可通过泛素过表达得以挽救的突变体。使用这种过表达策略筛选突变体时，鉴定出了 ，它编码内质网（ER）信号肽酶复合物（SPC）的一个亚基。泛素过表达挽救了 缺失突变体的高温敏感性，这表明泛素可以在高温下补偿Spc2功能的丧失。Spc2和内质网E3泛素连接酶Hrd1的双突变体在较高温度下表现出协同生长缺陷。在spc2Δ和 突变之间也观察到了微弱的遗传相互作用。结果表明酵母中SPC与泛素 - 蛋白酶体系统之间存在密切的功能关系，并进一步为这种泛素过表达方法鉴定新的泛素相关基因及相关细胞过程提供了原理证明。
