Tran Le Minh, Bang Seung Hyuck, Yoon Jihee, Kim Yang-Hoon, Min Jiho
Department of Bioprocess Engineering, Chonbuk National University, 664-14 Duckjin-dong, Jeonju, 561-756, South Korea.
Department of Chemical Engineering, Chonbuk National University, 664-14 Deokjin-dong, 1 Ga Deokjin-Gu, Jeonju, 561-756, South Korea.
Mol Cell Biochem. 2016 Mar;414(1-2):179-86. doi: 10.1007/s11010-016-2670-9. Epub 2016 Feb 19.
Yeast GTP-binding protein (YPT1 protein) has been reported to function in the early stages of the secretory pathway. Particularly, YPT1 protein is observed to regulate both the endoplasmic reticulum-to-Golgi transport and the autophagy. Therefore, the YPT1 protein overexpressed in yeast vacuoles is expected to enhance antimicrobial and anticancer activity. The enhancement of yeast vacuolar activity under the overexpression of YPT1 was evaluated by the analysis of lysozyme activity, antimicrobial activity against Escherichia coli and Staphylococcus aureus, and MTT assay against HeLa cell lines. Additionally, the rise in concentration of some important proteinases inside the vacuole, such as proteinase A, proteinase B, and vacuolar carboxypeptidase Y (CPY) were also recorded using a 2DE technique. All results imply YPT1 involvement in the recruitment of some specific proteinases into vacuoles, which leads to the enhancement of vacuolar activity. Since these there proteinases belong to the CPY pathway, YPT1 is even believed to up-regulate this trafficking pathway in yeast cells. Future studies, however, should be carried out to discover the mechanisms that allow YPT1 to recruit these proteins into yeast vacuoles.
据报道，酵母GTP结合蛋白（YPT1蛋白）在分泌途径的早期阶段发挥作用。特别是，观察到YPT1蛋白可调节内质网到高尔基体的运输以及自噬。因此，预计在酵母液泡中过表达的YPT1蛋白会增强抗菌和抗癌活性。通过溶菌酶活性分析、对大肠杆菌和金黄色葡萄球菌的抗菌活性以及对HeLa细胞系的MTT分析，评估了YPT1过表达情况下酵母液泡活性的增强。此外，还使用二维电泳技术记录了液泡内一些重要蛋白酶（如蛋白酶A、蛋白酶B和液泡羧肽酶Y（CPY））浓度的升高。所有结果表明YPT1参与了将一些特定蛋白酶招募到液泡中，这导致了液泡活性的增强。由于这三种蛋白酶属于CPY途径，甚至有人认为YPT1上调了酵母细胞中的这种运输途径。然而，未来的研究应该开展，以发现使YPT1将这些蛋白质招募到酵母液泡中的机制。
