摘要：SummaryDistinct sub-assemblies (modules) of mitochondrial complex I (CI) are assembled with the assistance of CI Assembly Factors (CIAFs) through mechanisms that are incompletely defined. Here, using genetic analyses inDrosophila, we report that when either of the CIAFs – NDUFAF3 or NDUFAF4 – is disrupted, biogenesis of the Q-, N-, and PP-b-modules of CI is impaired. This is due, at least in part, to the compromised integration of NDUFS3 and NDUFS5 into the Q-, and PP-b-modules, respectively, coupled with a destabilization of another CIAF, TIMMDC1, in assembly intermediates. Notably, forced expression of NDUFAF4 rescues the biogenesis defects in the Q-module and some aspects of the defects in the PP-b-module of CI when NDUFAF3 is disrupted. Altogether, our studies furnish new fundamental insights into the mechanism by which NDUFAF3 and NDUFAF4 regulate CI assembly and raises the possibility that certain point mutations in NDUFAF3 may be rescued by overexpression of NDUFAF4.Graphical abstractDisplay OmittedHighlights•Disruption of NDUFAF3 and NDUFAF4 in Drosophila muscles destabilizes TIMMDC1•NDUFAF3 and NDUFAF4 regulate biogenesis of the N, Q, and Pp modules•NDUFAF4 ameliorates some of the CI biogenesis defects in NDUFAF3 mutantsMolecular genetics; Molecular mechanism of gene regulation; Metabolic Engineering
