Cross-linking ATP synthase complexes in vivo eliminates mitochondrial cristae.
We have used the tetrameric nature of the fluorescent protein DsRed to cross-link F(1)F(O)-ATPase complexes incorporating a subunit gamma-DsRed fusion protein in vivo. Cells expressing such a fusion protein have impaired growth relative to control cells. Strikingly, fluorescence microscopy of these cells revealed aberrant mitochondrial morphology. Electron microscopy of cell sections revealed the absence of cristae and multiple layers of unfolded inner mitochondrial membrane. Complexes recovered from detergent lysates of mitochondria were present largely as tetramers. Co-expression of 'free' DsRed targeted to the mitochondria reduced F(1)F(O)-ATPase oligomerisation and partially reversed the impaired growth and abnormal mitochondrial morphology. We conclude that the correct arrangement of F(1)F(O)-ATPase complexes within the mitochondrial inner membrane is crucial for the genesis and/or maintenance of mitochondrial cristae and morphology. Our findings further suggest that F(1)F(O)-ATPase can exist in oligomeric associations within the membrane during respiratory growth.
Gavin
Paul D
PD
Department of Biochemistry & Molecular Biology, and ARC Centre for Structural and Functional Microbial Genomics, Monash University, Clayton campus, Victoria 3800, Australia.
Prescott
Mark
M
Luff
Susan E
SE
Devenish
Rodney J
RJ
D002455:Cell Division; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000378:metabolism*; D007425:Intracellular Membranes / Q000201:enzymology* / Q000473:pathology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology* / Q000473:pathology; D025261:Mitochondrial Proton-Translocating ATPases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000201:enzymology* / Q000235:genetics
D003432:Cross-Linking Reagents; D008164:Luminescent Proteins; D046912:Multiprotein Complexes; D011993:Recombinant Fusion Proteins; C413663:fluorescent protein 583; D025261:Mitochondrial Proton-Translocating ATPases; C444660:gamma subunit, F(1) ATPase; D006180:Proton-Translocating ATPases