Official websites use. Share sensitive information only on official, secure websites. Correspondence: nikolaus. The mitochondrial inner membrane plays central roles in bioenergetics and metabolism and contains several established membrane protein complexes. Here, we report the identification of a mega-complex of the inner membrane, termed mitochondrial multifunctional assembly MIMAS. MIMAS combines proteins of diverse functions from respiratory chain assembly to metabolite transport, dehydrogenases, and lipid biosynthesis but not the large established supercomplexes of the respiratory chain, ATP synthase, or prohibitin scaffold.
MIMAS integrity depends on the non-bilayer phospholipid phosphatidylethanolamine, in contrast to respiratory supercomplexes whose stability depends on cardiolipin. Our findings suggest that MIMAS forms a protein-lipid mega-assembly in the mitochondrial inner membrane that integrates respiratory biogenesis and metabolic processes in a multifunctional platform. Horten et al. The mitochondrial multifunctional assembly MIMAS includes proteins for respiratory chain biogenesis, metabolism, and phospholipid biosynthesis.
MIMAS reveals a higher-level organization of a protein-rich membrane by integrating diverse functions into a protein-lipid mega-assembly. Mitochondria contain membrane protein complexes that play crucial roles in respiration, ATP synthesis, protein biogenesis, and membrane organization. The systematic mapping of the mitochondrial proteome promoted the identification of a large number of mitochondrial proteins and functions.
The structures, functions, and complexome organization of respiratory supercomplexes, F 1 F o -ATP synthase, preprotein translocases, chaperone complexes, prohibitin scaffolds, and machineries for maintenance of membrane shape provide important insight into the molecular mechanisms and composition of mitochondria.
However, numerous mitochondrial proteins such as respiratory chain assembly factors and metabolite carriers have not been found as subunits of known mitochondrial protein complexes, although pull-down and crosslinking mass spectrometry studies reported interactions between some of the proteins.
