Eldeeb 2023 Abstract IOC162
|Eldeeb M, Fontanesi F (2023) Differential substrate utilization by mitochondrial respiratory supercomplexes. Mitochondr Physiol Network 28.02|
The function of the multimeric complexes (CI-CIV) that compose the mitochondrial respiratory chain is essential for ATP synthesis and cell survival. The organization of respiratory complexes into supramolecular structures of various stoichiometries, known as supercomplexes (SCs), is well-established and evolutionarily conserved. However, SC functional relevance is a matter of investigation and debate. To better understand SC function in the yeast Saccharomyces cerevisiae, we have fused subunits of CIII and CIV to force the assembly of only one type of SC, with a CIII dimer bound to two CIV monomers (III2IV2). Cryo-electron microscopy single particle analysis shows that these tethered SCs (T-SCs) do not exhibit any large structural defects. Additionally, T-SCs are functional, as yeast cells that assemble them grow equally to wild-type cells on non-fermentable media. Interestingly, mitochondria isolated from a strain expressing T-SCs respire NADH less efficiently than wild-type mitochondria, while no significant differences were observed with other respiratory substrates, such as pyruvate or succinate. Our preliminary data suggest a role of SCs in differential substrate utilization.
Labels: MiParea: Respiration
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA.