Biochimica et Biophysica Acta (BBA) - Molecular Cell Research ( IF 5.1 ) Pub Date : 2021-08-25 , DOI: 10.1016/j.bbamcr.2021.119133 Bettina Homberg 1 , Katharina Römpler 1 , Mirjam Wissel 1 , Sylvie Callegari 2 , Markus Deckers 3
The respiratory chain, embedded in the inner mitochondrial membrane, is organized as a network of individual complexes, as well as large supercomplex structures. In the yeast S. cerevisiae, these supercomplexes consist of a dimeric cytochrome bc1-complex adjoined by one or two copies of cytochrome c oxidase. The formation of these complexes is a dynamic process and is regulated by various factors in order to adapt to environmental and metabolic changes. These adaptions occur at the level of enzyme regulation, complex assembly, as well as altered nuclear and mitochondrial transcription and translation. Members of the Rcf protein family (Rcf1, Rcf2 and Rcf3) are required for respiratory complex biogenesis and act mainly by regulating the assembly and enzyme activity of complex IV within supercomplexes. Rcf1 functions in the assembly process via the COX3 module, whereas Rcf2 and Rcf3 are responsible for enzymatic regulation. In this study, we have extended this knowledge to show that Rcf2 and Rcf3 can also associate with newly synthesized mitochondrial encoded proteins, such as Cox3, and therefore contribute to complex IV assembly. Since the Rcf proteins have overlapping regions of sequence similarities, we engineered novel fusion proteins of Rcf1 and Rcf3, with parts of Rcf2, to probe which of the Rcf protein domains can be attributed to their functions. The fusion proteins could compensate for the individual phenotypes of the complexIV assembly defect and the lack of complex IV regulation. Finally, the role of Rcf proteins for defined species of respiratory chain complexes in a hypoxic model was investigated, uncovering a unique association of Rcf2 with the hypoxic III2IV supercomplex. We therefore suggest an involvement of Rcf2 for adaption of the respiratory chain to altering oxygen levels.
中文翻译:
Rcf 蛋白及其对呼吸链复合物的差异特异性:Rcf2 对氧敏感超级复合物的独特作用?
嵌入线粒体内膜的呼吸链被组织成一个由单个复合物和大型超级复合物结构组成的网络。在酵母S. cerevisiae 中,这些超级复合物由二聚体细胞色素bc 1 -复合物与一或两个细胞色素c拷贝相邻组成。氧化酶。这些复合物的形成是一个动态过程,受各种因素的调控,以适应环境和代谢的变化。这些适应发生在酶调节、复杂组装以及改变的核和线粒体转录和翻译水平上。Rcf 蛋白家族的成员(Rcf1、Rcf2 和 Rcf3)是呼吸复合物生物发生所必需的,主要通过调节超级复合物中复合物 IV 的组装和酶活性来发挥作用。Rcf1 通过 COX3 模块在组装过程中起作用,而 Rcf2 和 Rcf3 负责酶促调节。在这项研究中,我们扩展了这一知识以表明 Rcf2 和 Rcf3 还可以与新合成的线粒体编码蛋白(如 Cox3)相关联,因此有助于复杂的 IV 组装。由于 Rcf 蛋白具有序列相似性的重叠区域,我们设计了 Rcf1 和 Rcf3 的新型融合蛋白,以及 Rcf2 的一部分,以探查哪些 Rcf 蛋白结构域可归因于它们的功能。融合蛋白可以补偿 complexIV 组装缺陷的个体表型和复杂 IV 调节的缺乏。最后,研究了 Rcf 蛋白对缺氧模型中特定种类的呼吸链复合物的作用,揭示了 Rcf2 与缺氧 III 的独特关联 融合蛋白可以补偿 complexIV 组装缺陷的个体表型和复杂 IV 调节的缺乏。最后,研究了 Rcf 蛋白对缺氧模型中特定种类的呼吸链复合物的作用,揭示了 Rcf2 与缺氧 III 的独特关联 融合蛋白可以补偿 complexIV 组装缺陷的个体表型和复杂 IV 调节的缺乏。最后,研究了 Rcf 蛋白对缺氧模型中特定种类的呼吸链复合物的作用,揭示了 Rcf2 与缺氧 III 的独特关联2 IV 超复合体。因此,我们建议 Rcf2 参与呼吸链的适应以改变氧气水平。