Rosas-Lemus Mónica, Uribe-Alvarez Cristina, Chiquete-Félix Natalia, Uribe-Carvajal Salvador
Department of Molecular Genetics, Inst. de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico.
Department of Molecular Genetics, Inst. de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico.
Arch Biochem Biophys. 2014 Aug;555-556:66-70. doi: 10.1016/j.abb.2014.05.027. Epub 2014 Jun 9.
In Saccharomyces cerevisiae addition of glucose inhibits oxygen consumption, i.e. S. cerevisiae is Crabtree-positive. During active glycolysis hexoses-phosphate accumulate, and probably interact with mitochondria. In an effort to understand the mechanism underlying the Crabtree effect, the effect of two glycolysis-derived hexoses-phosphate was tested on the S. cerevisiae mitochondrial unspecific channel (ScMUC). Glucose-6-phosphate (G6P) promoted partial opening of ScMUC, which led to proton leakage and uncoupling which in turn resulted in, accelerated oxygen consumption. In contrast, fructose-1,6-bisphosphate (F1,6BP) closed ScMUC and thus inhibited the rate of oxygen consumption. When added together, F1,6BP reverted the mild G6P-induced effects. F1,6BP is proposed to be an important modulator of ScMUC, whose closure contributes to the "Crabtree effect".
在酿酒酵母中，添加葡萄糖会抑制氧气消耗，即酿酒酵母是具有克奈特效应（Crabtree效应）的。在活跃的糖酵解过程中，磷酸己糖会积累，并可能与线粒体相互作用。为了理解克奈特效应背后的机制，测试了两种糖酵解衍生的磷酸己糖对酿酒酵母线粒体非特异性通道（ScMUC）的影响。6-磷酸葡萄糖（G6P）促进了ScMUC的部分开放，这导致质子泄漏和解偶联，进而加速了氧气消耗。相反，1,6-二磷酸果糖（F1,6BP）关闭了ScMUC，从而抑制了氧气消耗速率。当两者一起添加时，F1,6BP逆转了轻度G6P诱导的效应。F1,6BP被认为是ScMUC的重要调节剂，其关闭有助于“克奈特效应”。
