Romero-Aguilar Lucero, Hernández-Morfín Katia Daniela, Guerra-Sánchez Guadalupe, Pardo Juan Pablo
Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Interior, Ciudad Universitaria, Coyoacán, Ciudad de México C.P. 04510, Mexico.
Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Carpio y Plan de Ayala S/N Santo Tomás, Miguel Hidalgo, Ciudad de México C.P. 11340, Mexico.
J Fungi (Basel). 2023 Jul 14;9(7):749. doi: 10.3390/jof9070749.
is an important model to study intermediary and mitochondrial metabolism, among other processes. can grow, at very different rates, on glucose, lactate, glycerol, and ethanol as carbon sources. Under nitrogen starvation and glucose as the only carbon source, this fungus synthesizes and accumulates neutral lipids in the form of lipid droplets (LD). In this work, we studied the accumulation of triacylglycerols in cells cultured in a medium containing acetate, a direct precursor of the acetyl-CoA required for the synthesis of fatty acids. The metabolic adaptation of cells to acetate was studied by measuring the activities of key enzymes involved in glycolysis, gluconeogenesis, and the pentose phosphate pathways. Since growth on acetate induces oxidative stress, the activities of some antioxidant enzymes were also assayed. The results show that cells grown in acetate plus nitrate did not increase the amount of LD, but increased the activities of glutathione reductase, glutathione peroxidase, catalase, and superoxide dismutase, suggesting a higher production of reactive oxygen species in cells growing in acetate. The phosphofructokinase-1 (PFK1) was the enzyme with the lowest specific activity in the glycolytic pathway, suggesting that PFK1 controls the flux of glycolysis. As expected, the activity of the phosphoenolpyruvate carboxykinase, a gluconeogenic enzyme, was present only in the acetate condition. In summary, in the presence of acetate as the only carbon source, synthesized fatty acids, which were directed into the production of phospholipids and neutral lipids for biomass generation, but without any excessive accumulation of LD.
是研究中间代谢和线粒体代谢等过程的重要模型。它能够以非常不同的速率在葡萄糖、乳酸、甘油和乙醇作为碳源的情况下生长。在氮饥饿且葡萄糖作为唯一碳源的条件下，这种真菌会合成并以脂滴（LD）的形式积累中性脂质。在这项工作中，我们研究了在含有乙酸盐（脂肪酸合成所需乙酰辅酶A的直接前体）的培养基中培养的细胞中三酰甘油的积累情况。通过测量参与糖酵解、糖异生和磷酸戊糖途径的关键酶的活性，研究了细胞对乙酸盐的代谢适应性。由于在乙酸盐上生长会诱导氧化应激，因此还测定了一些抗氧化酶的活性。结果表明，在乙酸盐加硝酸盐中生长的细胞没有增加脂滴的数量，但增加了谷胱甘肽还原酶、谷胱甘肽过氧化物酶、过氧化氢酶和超氧化物歧化酶的活性，这表明在乙酸盐中生长的细胞中活性氧的产生更高。磷酸果糖激酶-1（PFK1）是糖酵解途径中比活性最低的酶，这表明PFK1控制着糖酵解的通量。正如预期的那样，糖异生酶磷酸烯醇式丙酮酸羧激酶的活性仅在乙酸盐条件下存在。总之，在乙酸盐作为唯一碳源存在的情况下，合成了脂肪酸，这些脂肪酸被用于生成生物量的磷脂和中性脂质的生产，但没有脂滴的任何过度积累。
