Rcf proteins and their differential specificity for respiratory chain complexes: A unique role for Rcf2 on oxygen sensitive supercomplexes?

Homberg, Bettina; Römpler, Katharina; Wissel, Mirjam; Callegari, Sylvie; Deckers, Markus

doi:10.1016/j.bbamcr.2021.119133

Cited by 4 publications

(3 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rcf2 is a fungi-specific protein involved in the assembly of CIV ( 46 – 49 ). The protein is composed of a conserved hypoxia-induced gene domain 1 (HIG1) ( 50 – 53 ) and additional ~100 amino-acid residues form two transmembrane α-helices at the N-terminus ( 54 ). As in the earlier cryo-EM structures, we observed only the two HIG1-domain transmembrane α-helices interacting with Cox3 and Cox13.…”

Section: Resultsmentioning

confidence: 99%

Structure and function of theS. pombeIII–IV–cytcsupercomplex

Moe,

Dimogkioka,

Rapaport

et al. 2023

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The respiratory chain in aerobic organisms is composed of a number of membrane-bound protein complexes that link electron transfer to proton translocation across the membrane. In mitochondria, the final electron acceptor, complex IV (CIV), receives electrons from dimeric complex III (CIII2), via a mobile electron carrier, cytochromec. In the present study, we isolated the CIII2CIV supercomplex from the fission yeastSchizosaccharomyces pombeand determined its structure with bound cyt.cusing single-particle electron cryomicroscopy. A respiratory supercomplex factor 2 was found to be bound at CIV distally positioned in the supercomplex. In addition to the redox-active metal sites, we found a metal ion, presumably Zn2+, coordinated in the CIII subunit Cor1, which is encoded by the same gene (qcr1) as the mitochondrial-processing peptidase subunit β. Our data show that the isolated CIII2CIV supercomplex displays proteolytic activity suggesting a dual role of CIII2inS. pombe. As in the supercomplex fromS. cerevisiae, subunit Cox5 of CIV faces towards one CIII monomer, but inS. pombe,the two complexes are rotated relative to each other by ~45°. This orientation yields equal distances between the cyt.cbinding sites at CIV and at each of the two CIII monomers. The structure shows cyt.cbound at four positions, but only along one of the two symmetrical branches. Overall, this combined structural and functional study reveals the integration of peptidase activity with the CIII2respiratory system and indicates a two-dimensional cyt.cdiffusion mechanism within the CIII2–CIV supercomplex.

show abstract

Section: Resultsmentioning

confidence: 99%

Structure and function of theS. pombeIII–IV–cytcsupercomplex

Moe,

Dimogkioka,

Rapaport

et al. 2023

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…CC-BY-NC 4.0 International license made available under a abundance, but alters the activity of the enzyme (Strogolova et al, 2019). Complementation studies in yeast show that RCF1 and RCF2 are not functionally redundant (Homberg et al, 2021;Rompler et al, 2016). Yeast mitochondrial lacking both RCF proteins have lower mitochondrial membrane potential and the respiratory chain becomes inactive over time (Strogolova et al, 2019).…”

Section: Enod93 Is Similar To the N-terminus Of Rcf2 And They Share A...mentioning

confidence: 99%

“…In mutants lacking both RCF1 and RCF2 proteins there is a proton leak back through complex IV, suggesting that the HIG domains of RCFs might be involved in preventing proton leak from the IMS to the matrix through complex IV (Hoang et al, 2019). Recently it was also found that fusing the RCF2 N-terminus to RCF1 could rescue an Δrcf2Δrcf3 mutant (Homberg et al, 2021) which was surprising as previously the focus had been only on the RCF2 C-terminal HIG domain as having unique capabilities in the regulation of complex IV activity (Rompler et al, 2016).…”

Section: Enod93 Is Similar To the N-terminus Of Rcf2 And They Share A...mentioning

confidence: 99%

ENOD93 interacts with cytochrome c oxidase altering respiratory ATP production and root growth in plants

Lee

Gawryluk

et al. 2023

Preprint

View full text Add to dashboard Cite

The early nodulin 93 (ENOD93) gene family in plants can regulate biological nitrogen fixation in legumes and nitrogen use efficiency in cereals but its molecular function is unknown. We show profile hidden Markov models define ENOD93 as a distant homolog of the N-terminal domain of RESPIRATORY SUPERCOMPLEX FACTOR 2 (RCF2). RCF2 is reported to regulate cytochrome oxidase (CIV) influencing the generation of a mitochondria proton motive force in yeast. Knockout of enod93 in Arabidopsis leads to a short root phenotype. ENOD93 is associated with a protein complex the size of CIV in isolated mitochondria but neither CIV abundance nor its activity in ruptured organelles changed in enod93. However, a progressive loss of ADP-dependent respiration rate was observed in enod93 mitochondria which could be fully recovered in complemented lines. Mitochondrial membrane potential was higher in enod93 but ATP synthesis and ADP depletion rates progressively decreased. Respiration rate of whole enod93 seedlings was elevated and root ADP content was nearly double that in WT without a change in ATP content. These altered energetic states correlated with elevated respiratory substrate levels in roots of enod93 compared to WT and complemented lines. Overexpression of ENOD93 lowered ATP content in roots and increased the abundance of a range of amino acids in both roots and leaves. We propose that two previously unconnected gene families in plants, ENOD93 and HYPOXIA INDUCED GENE DOMAIN, are the functional equivalent of yeast RCF2 but have remained undiscovered in many eukaryotic lineages because they are encoded in two separate genes.

show abstract

Mitochondrial respiratory supercomplexes of the yeast Saccharomyces cerevisiae

Eldeeb,

Camacho Lopez,

Fontanesi

2024

IUBMB Life

View full text Add to dashboard Cite

The functional and structural relationship among the individual components of the mitochondrial respiratory chain constitutes a central aspect of our understanding of aerobic catabolism. This interplay has been a subject of intense debate for over 50 years. It is well established that individual respiratory enzymes associate into higher‐order structures known as respiratory supercomplexes, which represent the evolutionarily conserved organizing principle of the mitochondrial respiratory chain. In the yeast Saccharomyces cerevisiae, supercomplexes are formed by a complex III homodimer flanked by one or two complex IV monomers, and their high‐resolution structures have been recently elucidated. Despite the wealth of structural information, several proposed supercomplex functions remain speculative and our understanding of their physiological relevance is still limited. Recent advances in the field were made possible by the construction of yeast strains where the association of complex III and IV into supercomplexes is impeded, leading to diminished respiratory capacity and compromised cellular competitive fitness. Here, we discuss the experimental evidence and hypotheses relative to the functional roles of yeast respiratory supercomplexes. Moreover, we review the current models of yeast complex III and IV assembly in the context of supercomplex formation and highlight the data scattered throughout the literature suggesting the existence of cross talk between their biogenetic processes.

show abstract

Rcf proteins and their differential specificity for respiratory chain complexes: A unique role for Rcf2 on oxygen sensitive supercomplexes?

Cited by 4 publications

References 37 publications

Structure and function of theS. pombeIII–IV–cytcsupercomplex

Structure and function of theS. pombeIII–IV–cytcsupercomplex

ENOD93 interacts with cytochrome c oxidase altering respiratory ATP production and root growth in plants

Mitochondrial respiratory supercomplexes of the yeast Saccharomyces cerevisiae

Contact Info

Product

Resources

About