Abstract
The mitochondrial presequence translocase interacts with presequence-containing precursors at the intermembrane space (IMS) side of the inner membrane to mediate their translocation into the matrix. Little is known as too how these matrix-targeting signals activate the translocase in order to initiate precursor transport. Therefore, we analysed how signal recognition by the presequence translocase initiates reorganization among Tim-proteins during import. Our analyses revealed that the presequence receptor Tim50 interacts with Tim21 in a signal-sensitive manner in a process that involves the IMS-domain of the Tim23 channel. The signal-driven release of Tim21 from Tim50 promotes recruitment of Pam17 and thus triggers formation of the motor-associated form of the TIM23 complex required for matrix transport.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Binding Sites
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Carrier Proteins / genetics
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Carrier Proteins / metabolism*
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Membrane Proteins / chemistry
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Membrane Transport Proteins / chemistry
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Membrane Transport Proteins / genetics
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Membrane Transport Proteins / metabolism
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Membrane Transport Proteins / physiology*
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Mitochondrial Membrane Transport Proteins / chemistry
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Mitochondrial Membrane Transport Proteins / genetics
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Mitochondrial Membrane Transport Proteins / metabolism
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Mitochondrial Membrane Transport Proteins / physiology
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Mitochondrial Precursor Protein Import Complex Proteins
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Models, Molecular
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Protein Binding
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Protein Interaction Domains and Motifs / genetics
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Protein Interaction Domains and Motifs / physiology
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Protein Sorting Signals / genetics
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Protein Sorting Signals / physiology*
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Protein Structure, Secondary
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Protein Transport* / genetics
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism
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Saccharomyces cerevisiae Proteins / chemistry
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism
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Saccharomyces cerevisiae Proteins / physiology
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Substrate Specificity
Substances
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Carrier Proteins
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Membrane Proteins
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Membrane Transport Proteins
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Mitochondrial Membrane Transport Proteins
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Mitochondrial Precursor Protein Import Complex Proteins
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Pam17 protein, S cerevisiae
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Protein Sorting Signals
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Saccharomyces cerevisiae Proteins
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TIM23 protein, S cerevisiae
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TIM50 protein, S cerevisiae
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Tim21 protein, S cerevisiae