Mitochondrial F1Fo-ATP Synthase: The Small Subunits e and g Associate with Monomeric Complexes to Trigger Dimerization

MINOS1 is a conserved component of mitofilin complexes and required for mitochondrial function and cristae organization

“…However, Atp20, Atp21, Atp19, and Atp18 are not essential for ATPase activity (Arnold et al, 1997, 1998, 1999; Vaillier et al, 1999; Rabl et al, 2009). Atp18, Atp20, and Atp21 are of low molecular weight (around 12 kDa) and contain predicted membrane-spanning regions (Arnold et al, 1997, 1998; Soubannier et al, 2002; Paumard et al, 2002a; Wagner et al, 2009, 2010). Furthermore, subunits Atp20 and Atp21 contain a characteristic GxxxG motif in their transmembrane domain.…”

Stepwise Assembly of Dimeric F1Fo-ATP Synthase in Mitochondria Involves the Small Fo-Subunits k and i

“…With antisera against the peripheral stalk subunits Su b and Su h and the small F o -subunit Su i, we detected two monomeric forms of F 1 F o -ATP synthase, M and M' (Figure 1A, lanes 1–3). We have shown previously that the primed monomer M' also contains Su e and Su g (Wagner et al , 2009). Interestingly, we also observed two different forms of the ATP synthase dimer with slightly different migration behavior, which we termed D and D' (Figure 1A).…”

“…Depending on the type and concentration of the detergent used to solubilize mitochondrial membranes monomeric, dimeric and higher oligomeric forms of ATP synthase have been separated with these methods (Arnold et al , 1998; Schägger and Pfeiffer, 2000; Paumard et al , 2002a; Eubel et al , 2003; Gavin et al , 2005; Bornhövd et al , 2006; Dudkina et al , 2006; Wittig et al , 2008). To get more insight into the oligomeric organization of yeast F 1 F o -ATP synthase, we have established conditions for blue native electrophoresis that allow the optimal separation of protein complexes in the high-molecular-weight range (high-resolution BN-PAGE; Wagner et al , 2009). We isolated mitochondria from a wild-type S.…”

“…Deletion of the ATP18 and ATP19 genes encoding Su i and Su k, respectively, was achieved by homologous recombination of a His3MX6 cassette into the corresponding locus (Longtine et al , 1998). Strains atp20 Δ (lacking Su g) and atp21 Δ (lacking Su e) have been described previously (Wagner et al , 2009). For preparation of mitochondria, yeast deletion mutants and the corresponding wild-type cells were grown in YPG medium (1% [wt/vol] yeast extract, 2% [wt/vol] peptone, and 3% [vol/vol] glycerol) at 30°C.…”

“…Two of these subunits, Su e (Atp21/Tim11) and Su g (Atp20), were shown to be critical for the stability of F 1 F o -ATP synthase dimers (Arnold et al , 1998; Paumard et al , 2002a; Bornhövd et al , 2006; Wittig et al , 2008). Su e and Su g assemble with monomeric ATP synthase in a sequential manner to form a dimerization-competent primed monomer (Wagner et al , 2009). Deletion of the nuclear genes encoding Su e and Su g strongly inhibits dimer formation and leads to an aberrant, onion-like cristae morphology (Giraud et al , 2002; Paumard et al , 2002a; Arselin et al , 2004; Rabl et al , 2009).…”