Yi Dae-Gwan, Huh Won-Ki
Department of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea.
Department of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea; Institute of Microbiology, Seoul National University, Seoul 151-747, Republic of Korea.
Biochem Biophys Res Commun. 2015 Nov 27;467(4):657-63. doi: 10.1016/j.bbrc.2015.10.090. Epub 2015 Oct 21.
Ugp1, UDP-glucose pyrophosphorylase, plays an important role in carbohydrate metabolism because it provides UDP-glucose that is a pivotal metabolite in several metabolic pathways in Saccharomyces cerevisiae. In this study, we show that a considerable reduction of glycogen and trehalose content in ugp1 knockdown cells is rescued by complementing the expression of Ugp1, indicating that Ugp1 is required for the production of storage carbohydrates. Because of the specific function of trehalose as a stress protectant, Ugp1 expression contributed to oxidative stress response and long-term cell survival during stationary phase. Furthermore, the modulation of Ugp1 level readjusted glycogen and trehalose accumulation in the protein kinase A (PKA)-related gene mutants. The PKA-dependent phenotypes of oxidative stress resistance and long-term cell survival were also alleviated via adjustment of Ugp1 level. Collectively, our data suggest that the regulation of UPG1 influences several PKA-dependent processes by adjusting the levels of various carbohydrates.
Ugp1,即尿苷二磷酸葡萄糖焦磷酸化酶,在碳水化合物代谢中发挥着重要作用,因为它能提供尿苷二磷酸葡萄糖,这是酿酒酵母中多种代谢途径的关键代谢物。在本研究中,我们发现通过补充Ugp1的表达,可挽救ugp1基因敲低细胞中糖原和海藻糖含量的显著降低,这表明Ugp1是储存碳水化合物产生所必需的。由于海藻糖作为应激保护剂的特殊功能,Ugp1的表达有助于氧化应激反应以及静止期的长期细胞存活。此外,Ugp1水平的调节重新调整了蛋白激酶A(PKA)相关基因突变体中糖原和海藻糖的积累。通过调节Ugp1水平,氧化应激抗性和长期细胞存活的PKA依赖性表型也得到了缓解。总体而言,我们的数据表明,UPG1的调节通过调整各种碳水化合物的水平影响多个PKA依赖性过程。