Abstract
By screening yeast knockouts for their dependence upon the mitochondrial genome, we identified Mgr3p, a protein that associates with the i-AAA protease complex in the mitochondrial inner membrane. Mgr3p and Mgr1p, another i-AAA-interacting protein, form a subcomplex that bind to the i-AAA subunit Yme1p. We find that loss of Mgr3p, like the lack of Mgr1p, reduces proteolysis by Yme1p. Mgr3p and Mgr1p can bind substrate even in the absence of Yme1p, and both proteins are needed for maximal binding of an unfolded substrate by the i-AAA complex. We speculate that Mgr3p and Mgr1p function in an adaptor complex that targets substrates to the i-AAA protease for degradation.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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ATP-Dependent Proteases
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Adenosine Triphosphatases / genetics
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Adenosine Triphosphatases / metabolism
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Carrier Proteins / genetics
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Carrier Proteins / metabolism*
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Endopeptidases / genetics
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Endopeptidases / metabolism*
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Mitochondria / enzymology*
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Mitochondrial Membrane Transport Proteins
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Mitochondrial Membranes / enzymology
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Mitochondrial Proteins / genetics
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Mitochondrial Proteins / metabolism*
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Multienzyme Complexes / chemistry
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Multienzyme Complexes / metabolism*
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Saccharomyces cerevisiae / physiology
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism*
Substances
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Carrier Proteins
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Membrane Proteins
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Mgr1 protein, S cerevisiae
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Mgr3 protein, S cerevisiae
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Mitochondrial Membrane Transport Proteins
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Mitochondrial Proteins
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Multienzyme Complexes
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Saccharomyces cerevisiae Proteins
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Endopeptidases
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ATP-Dependent Proteases
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YME1 protein, S cerevisiae
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Adenosine Triphosphatases