Succinate dehydrogenase (SDH), also named as complex II or succinate:quinone oxidoreductases (SQR) is a critical enzyme in bioenergetics and metabolism. This is because the enzyme is located at the intersection of oxidative phosphorylation and tricarboxylic acid cycle (TCA); the two major pathways involved in generating energy within cells. SDH is composed of 4 subunits and is assembled through a multi-step process with the aid of assembly factors. Not surprisingly malfunction of this enzyme has marked repercussions in metabolism leading to devastating tumors such as paraganglioma and pheochromocytoma. It is already known that mutations in the genes encoding subunits lead to tumorigenesis, but recent discoveries have indicated that mutations in the genes encoding the assembly factors also contribute to tumorigenesis. The mechanisms of pathogenesis of tumorigenesis have not been fully understood. However, a multitude of signaling pathways including succinate signaling was determined. We, here discuss how defective SDH may lead to tumor development at the molecular level and describe how yeast, as a model system, has contributed to understanding the molecular pathogenesis of tumorigenesis resulting from defective SDH.

中文翻译：

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琥珀酸脱氢酶缺陷引起的肿瘤发生的分子发病机制。

琥珀酸脱氢酶（SDH），也称为复合物II或琥珀酸：醌氧化还原酶（SQR）是生物能和代谢中的关键酶。这是因为该酶位于氧化磷酸化和三羧酸循环（TCA）的交点处。细胞内产生能量的两个主要途径。SDH由4个子单元组成，并在组装因素的帮助下通过多步骤过程进行组装。毫不奇怪，这种酶的功能异常会在代谢中产生明显影响，导致破坏性肿瘤，如副神经节瘤和嗜铬细胞瘤。已经知道，编码亚基的基因中的突变会导致肿瘤发生，但是最近的发现表明，编码装配因子的基因中的突变也有助于肿瘤发生。尚未完全了解肿瘤发生的发病机理。然而，确定了包括琥珀酸信号传导在内的多种信号传导途径。我们在这里讨论有缺陷的SDH如何在分子水平上导致肿瘤发展，并描述酵母作为模型系统如何有助于理解由有缺陷的SDH引起的肿瘤发生的分子发病机理。