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The INA complex facilitates assembly of the peripheral stalk of the mitochondrial F 1 F o ‐ ATP synthase
Author(s) -
Lytovchenko Oleksandr,
Naumenko Nataliia,
Oeljeklaus Silke,
Schmidt Bernhard,
Malsburg Karina,
Deckers Markus,
Warscheid Bettina,
Laan Martin,
Rehling Peter
Publication year - 2014
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.201488076
Subject(s) - atp synthase , mitochondrial matrix , biology , mitochondrion , inner membrane , inner mitochondrial membrane , biogenesis , stalk , microbiology and biotechnology , cytosol , atp–adp translocase , biochemistry , enzyme , gene , horticulture
Mitochondrial F 1 F o ‐ ATP synthase generates the bulk of cellular ATP . This molecular machine assembles from nuclear‐ and mitochondria‐encoded subunits. Whereas chaperones for formation of the matrix‐exposed hexameric F 1 ‐ ATP ase core domain have been identified, insight into how the nuclear‐encoded F 1 ‐domain assembles with the membrane‐embedded F o ‐region is lacking. Here we identified the INA complex ( INAC ) in the inner membrane of mitochondria as an assembly factor involved in this process. Ina22 and Ina17 are INAC constituents that physically associate with the F 1 ‐module and peripheral stalk, but not with the assembled F 1 F o ‐ ATP synthase. Our analyses show that loss of Ina22 and Ina17 specifically impairs formation of the peripheral stalk that connects the catalytic F 1 ‐module to the membrane embedded F o ‐domain. We conclude that INAC represents a matrix‐exposed inner membrane protein complex that facilitates peripheral stalk assembly and thus promotes a key step in the biogenesis of mitochondrial F 1 F o ‐ ATP synthase.