Respiratory supercomplexes act as a platform for complex III-mediated maturation of human mitochondrial complexes I and IV.

ABSTRACT: Mitochondrial respiratory chain (MRC) enzymes associate in supercomplexes (SCs) that are structurally interdependent. This may explain why defects in a single component often produce combined enzyme deficiencies in patients. A case in point is the alleged destabilization of complex I in the absence of complex III. To clarify the structural and functional relationships between complexes, we have used comprehensive proteomic, functional, and biogenetical approaches to analyze a MT-CYB-deficient human cell line. We show that the absence of complex III blocks complex I biogenesis by preventing the incorporation of the NADH module rather than decreasing its stability. In addition, complex IV subunits appeared sequestered within complex III subassemblies, leading to defective complex IV assembly

SUBMITTER: Protasoni M 

PROVIDER: S-EPMC6996572 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature