A glycolytic metabolon in Saccharomyces cerevisiae is stabilized by F-actin
A glycolytic metabolon in Saccharomyces cerevisiae is stabilized by F-actin
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DOI：
10.1111/febs.12387
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发表时间：
2013-08-01
期刊：
影响因子：
5.4
通讯作者：
Uribe-Carvajal, Salvador
中科院分区：
文献类型：
--
作者：
Araiza-Olivera, Daniela;Chiquete-Felix, Natalia;Uribe-Carvajal, Salvador
在酿酒酵母的糖酵解途径中，11种酶催化葡萄糖逐步转化为两个乙醇分子和两个二氧化碳分子。在高度拥挤的细胞质中，如果依赖底物/酶的扩散，这一途径的效率将非常低下。因此，多酶糖酵解复合体的存在已被提出。这种复合体可能使用细胞骨架来稳定各种酶的相互作用。在这里，丝状肌动蛋白(F-肌动蛋白)在糖酵解代谢产物的稳定中的作用被报道。实验在分离的酶/肌动蛋白混合物、细胞质提取物和通透性酵母细胞中进行。使用鬼臼乙素可以促进肌动蛋白的聚合，而使用细胞松弛素D或丁香草素则可以抑制肌动蛋白的聚合。聚合丝状的F-肌动蛋白，而不是单体的球状G-肌动蛋白，稳定了分离的糖酵解途径酶混合物之间的相互作用和整个发酵途径，导致了更高的发酵活性。结合的复合体抵抗由于粘度(由二糖海藻糖促进)或失活(使用特定的酶抗体)造成的抑制。在酿酒酵母中，糖酵解代谢产物似乎与F-肌动蛋白结合在一起。在这个复合体中，发酵活性得到增强，酶被海藻糖或抗体部分保护而不受抑制。
In the Saccharomyces cerevisiae glycolytic pathway, 11 enzymes catalyze the stepwise conversion of glucose to two molecules of ethanol plus two CO2 molecules. In the highly crowded cytoplasm, this pathway would be very inefficient if it were dependent on substrate/enzyme diffusion. Therefore, the existence of a multi-enzymatic glycolytic complex has been suggested. This complex probably uses the cytoskeleton to stabilize the interaction of the various enzymes. Here, the role of filamentous actin (F-actin) in stabilization of a putative glycolytic metabolon is reported. Experiments were performed in isolated enzyme/actin mixtures, cytoplasmic extracts and permeabilized yeast cells. Polymerization of actin was promoted using phalloidin or inhibited using cytochalasin D or latrunculin. The polymeric filamentous F-actin, but not the monomeric globular G-actin, stabilized both the interaction of isolated glycolytic pathway enzyme mixtures and the whole fermentation pathway, leading to higher fermentation activity. The associated complexes were resistant against inhibition as a result of viscosity (promoted by the disaccharide trehalose) or inactivation (using specific enzyme antibodies). In S. cerevisiae, a glycolytic metabolon appear to assemble in association with F-actin. In this complex, fermentation activity is enhanced and enzymes are partially protected against inhibition by trehalose or by antibodies.