Coordination of metal center biogenesis in human cytochrome c oxidase

Abstract

Mitochondrial cytochrome c oxidase (CcO) or respiratory chain complex IV is a heme aa3-copper oxygen reductase containing metal centers essential for holo-complex biogenesis and enzymatic function that are assembled by subunit-specific metallochaperones. The enzyme has two copper sites located in the catalytic core subunits. The COX1 subunit harbors the CuB site that tightly associates with heme a3 while the COX2 subunit contains the binuclear CuA site. Here, we report that in human cells the CcO copper chaperones form macromolecular assemblies and cooperate with several twin CX9C proteins to control heme a biosynthesis and coordinate copper transfer sequentially to the CuA and CuB sites. These data on CcO illustrate a mechanism that regulates the biogenesis of macromolecular enzymatic assemblies with several catalytic metal redox centers and prevents the accumulation of cytotoxic reactive assembly intermediates.

APOE Expression and Secretion are Modulated by Mitochondrial Dysfunction

“…5B). We confirmed these findings with mutants in the complex IV assembly factors COX18 and 20 (Bourens and Barrientos, 2017; Nyvltova et al, 2022). COX18 and 20 gene defects increased APOE expression to the same extent as HIGD1A (Fig.…”

“…To test this hypothesis, we first determined the effects of SLC25A1 and SLC25A4 mutations on the organization of the electron transport chain by blue native electrophoresis. Second, we mutagenized assembly factors and subunits of complexes I (NDUFS3 and NDUFAF7), III (COX7A2L and HIGD1), and IV of the electron transport chain (COX7A2L, HIGD1A, COX17, 18, 19, and 20) to then measure APOE levels (Lobo-Jarne et al, 2018; Nyvltova et al, 2022; Timon-Gomez et al, 2020a; Zurita Rendon et al, 2014). We determined the robustness of the increased APOE phenotype studying mutants in three human cell lines (HAP1, SH-SY5Y, and HEK293), which differ in several properties, including their genetic background, rate of growth, and tissue of origin.…”

“…HEK293 cells knockout cell lines for HIGD1A, COX7A2L, COX18, COX19, and COX20 and their control cell line were grown in DMEM media (Corning, 10-013) containing 10% FBS (VWR, 97068-085), 50 µg/ml uridine (Sigma, U3003), and 1x GlutaMAX (Gibco, 35050061) at 37°C in 10% CO2. Details about the generation of the cell lines using TALEN can be found in Nývltová et al, 2022((Nyvltova et al, 2022, COX19), Bourens andBarrientos, 2017 ((Bourens andBarrientos, 2017), COX18), Lobo-Jarne et al, 2018((Lobo-Jarne et al, 2018, COX7A2L), Timón-Gómez et al, 2017((Timon-Gomez et al, 2020a, HIGD1A), and Bourens et al, 2014 ((Bourens andBarrientos, 2017), COX20).…”

Copper homeostasis and cuproptosis in health and disease

“…In humans, COX consists of two core subunits, COX1 and COX2, which bind Cu at the conserved Cu B and Cu A sites, respectively. 41 The Cu chaperone COX17, located in the IMS, is responsible for transporting Cu from the cytosol to the mitochondrial IMS and contributes to the assembly of COX. 15,42 In the IMS, Cu + is bound to COX17 and delivered either to the chaperone synthesis of cytochrome c oxidase 1 (SCO1) for transfer to the COX2 subunit, or to COX11 for delivery to the COX1 subunit [43][44][45] (Fig.…”

Recent Advances in Copper-Based Organic Complexes and Nanoparticles for Tumor Theranostics

“…As a result, copper ions readily form complexes with biomolecules containing these amino acid residues. Copper atoms are involved in a functioning of a wide spectrum of proteins, such as copper/zinc superoxide dismutase (Cu/Zn SOD or SOD1) [ 2 ], cytochrome c oxidase (COX) [ 3 ], lysyl oxidase (LOX) [ 4 ], mitogen-activated protein kinase MEK1 [ 5 ], and cAMP-degrading phosphodiesterase PDE3B [ 6 ]. In these proteins, copper ions participate in diverse biochemical reactions (especially redox reactions) of donating or accepting of electrons and maintain specific protein structures by coordinating with the abovementioned groups.…”