Selective Oma1 protease-mediated proteolysis of Cox1 subunit of cytochrome oxidase in assembly mutants.
Stalled biogenesis of the mitochondrial cytochrome c oxidase (CcO) complex results in degradation of subunits containing redox cofactors. The conserved Oma1 metalloproteinase mediates facile Cox1 degradation in cells lacking the Coa2 assembly factor, but not in a series of other mutants stalled in CcO maturation. Oma1 is activated in coa2Δ cells, but the selective Cox1 degradation does not arise merely from its activation. Oma1 is also active in cells with dysfunctional mitochondria and cox11Δ cells impaired in CcO maturation, but this activation does not result in Oma1-mediated Cox1 degradation. The facile and selective degradation of Cox1 in coa2Δ cells, relative to other CcO assembly mutants, is likely due to impaired hemylation and subsequent misfolding of the subunit. Specific Cox1 proteolysis in coa2Δ cells arises from a combination of Oma1 activation and a susceptible conformation of Cox1.
Department of Medicine and Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA.
Oleh
O
Khalimonchuk
Mi-Young
MY
Jeong
Talina
T
Watts
Elliott
E
Ferris
Dennis R
DR
Winge
D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D045726:Metalloproteases / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics; D009154:Mutation; D059748:Proteolysis; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
C530854:Coa2 protein, S cerevisiae; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; C526453:Cox1 protein, S cerevisiae; D003576:Electron Transport Complex IV; D045726:Metalloproteases; C480741:Oma1 protein, S cerevisiae