Human mitochondrial ATP synthase is an enzyme containing 18 unlike subunits located in the inner mitochondrial membrane (IMM), where the catalytic F1 domain extends into the mitochondrial matrix and the FO domain, which contains the c8-ring rotor, the a-subunit and the supernumerary subunits, is anchored in the IMM. All the subunits, apart from the a- and A6L-subunits, are encoded in the nucleus and require transport into the mitochondria before being assembled. The a- and A6L-subunits are encoded on the mitochondrial genome. The respiratory complexes generate the proton motive force (PMF), which ATP synthase uses to generate ATP from ADP and Pi. Rotation of the α- and β-subunits with the central stalk γ-, δ- and ε-subunits is prevented by coupling the F1 domain to the FO domain via the peripheral stalk (the OSCP-, F6-, d- and b-subunits). ATP hydrolysis is prevented by the natural inhibitor of the enzyme, IF1, binding to the F1 domain. In addition to the aand, b-subunits, the FO domain contains the c8-ring and six supernumerary subunits not involved in the catalytic activity of ATP synthase. The roles of five of these subunits in the assembly of ATP synthase, the e-, f-, g-, DAPIT- and 6.8 kDa proteolipid-subunits, were investigated by suppressing or disrupting their expression individually. The e-subunit is the first of the supernumerary subunits to assemble, then the g-subunit followed by the f-, 6.8 kDa proteolipid- and DAPIT-subunits. All five supernumerary subunits investigated were required to facilitate the dimerisation and oligomerisation of ATP synthase. The e-, f- and g-subunits were found to be important for maintaining mitochondrial respiratory capacity.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:725532 |
Date | January 2017 |
Creators | Douglas, Corsten Perrie Louise Claire |
Contributors | Walker, John |
Publisher | University of Cambridge |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | https://www.repository.cam.ac.uk/handle/1810/267744 |
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