About me
Bioengineering of Asymmetrical Mitochondrial Supercomplex III2IV1
Location: West Ballroom
Mentor: Dr.Flavia Fontanesi
The mitochondrial respiratory chain (MRC) is the central hub of ATP production in eukaryotic cells. Located in the mitochondrial inner membrane, it consists of four complexes (CI-IV), where CI, CII, CIII₂, and CIV transport electrons via coenzyme Q (CI or CII to CIII₂) and cytochrome c (CIII₂ to CIV), generating a proton gradient resulting in production of ATP by ATP synthase. Additionally, it was discovered that MRC complexes can assemble into higher-order supercomplexes (SCs). In Saccharomyces cerevisiae, the MRC contains three complexes (CII-IV); where CIII₂ and CIV can assemble into two SC conformations, III₂ IV₁ and III₂ IV₂, whose association is mediated mainly by interactions between CIII₂ subunit Cor1 and CIV subunit Cox5a. Introduction of point mutations in Cor1 disrupted this interaction and demonstrated that SCs increase electron transfer efficiency by enhancing diffusion of cytochrome c. To differentiate the roles of individual SC configurations, we aim to create and characterize an obligatory III₂ IV₁ strain to compare against the strain that cannot assemble SCs and an obligatory III₂ IV₂ SC strain. To break the inherent symmetry of CIII₂, we cloned several Cor1 fusion constructs containing two copies of Cor1 with varying linkage between them. We found that clones with the linker subunit 9, a CIII₂ subunit that exists between the two Cor1 subunits in mus muculus, are respiratory sufficient, whilst assembling SCs comparable to that of wild type. Finally, we aim to utilize point mutations on one of the Cor1 subunits to inhibit interactions with CIV on only one side.
