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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1
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pubmed:dateCreated |
1997-12-5
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pubmed:abstractText |
Transport of preproteins across the inner mitochondrial membrane requires the action of the matrix heat shock protein Hsp70. Together with its co-chaperone mitochondrial GrpE (Mge1), mtHsp70 transiently binds to the inner membrane translocase subunit Tim44 in a nucleotide-regulated manner, forming an ATP-dependent import driving machinery. We report that a mutant form of Mge1 (Mge1-100) is completely absent in mtHsp70-Tim44 complexes, although its ability to interact with soluble mtHsp70 is only partially reduced. While this mge1-100 mutation only partially retards preprotein translocation into the matrix, it exerts a selective effect on sorting of cytochrome b2 to the intermembrane space. A cytochrome b2 with an altered sorting signal, which is only processed to the intermediate stage and mistargeted to the matrix of wild-type mitochondria, is processed to the mature form and correctly targeted to the intermembrane space of mge1-100 mitochondria. These results suggest that (1) Mge1-100 discriminates between soluble and membrane-bound mtHsp70 and (2) the membrane-bound mtHsp70-Mge1 driving system competes with the sorting machinery for translocation of preproteins like cytochrome b2.
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Fungal Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/HSP70 Heat-Shock Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Heat-Shock Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/L-Lactate Dehydrogenase,
http://linkedlifedata.com/resource/pubmed/chemical/L-Lactate Dehydrogenase (Cytochrome),
http://linkedlifedata.com/resource/pubmed/chemical/MAS6 protein, S cerevisiae,
http://linkedlifedata.com/resource/pubmed/chemical/MGE1 protein, S cerevisiae,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Transport Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Mitochondrial Membrane Transport...,
http://linkedlifedata.com/resource/pubmed/chemical/Molecular Chaperones,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Precursors,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Sorting Signals,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Saccharomyces cerevisiae Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/TIM44 protein, S cerevisiae,
http://linkedlifedata.com/resource/pubmed/chemical/Tetrahydrofolate Dehydrogenase
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pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0022-2836
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
17
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pubmed:volume |
273
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1-6
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:9367739-Blotting, Western,
pubmed-meshheading:9367739-Carrier Proteins,
pubmed-meshheading:9367739-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:9367739-Fungal Proteins,
pubmed-meshheading:9367739-HSP70 Heat-Shock Proteins,
pubmed-meshheading:9367739-Heat-Shock Proteins,
pubmed-meshheading:9367739-Intracellular Membranes,
pubmed-meshheading:9367739-L-Lactate Dehydrogenase,
pubmed-meshheading:9367739-L-Lactate Dehydrogenase (Cytochrome),
pubmed-meshheading:9367739-Membrane Proteins,
pubmed-meshheading:9367739-Membrane Transport Proteins,
pubmed-meshheading:9367739-Mitochondria,
pubmed-meshheading:9367739-Mitochondrial Membrane Transport Proteins,
pubmed-meshheading:9367739-Molecular Chaperones,
pubmed-meshheading:9367739-Mutagenesis, Site-Directed,
pubmed-meshheading:9367739-Precipitin Tests,
pubmed-meshheading:9367739-Protein Precursors,
pubmed-meshheading:9367739-Protein Processing, Post-Translational,
pubmed-meshheading:9367739-Protein Sorting Signals,
pubmed-meshheading:9367739-Recombinant Fusion Proteins,
pubmed-meshheading:9367739-Saccharomyces cerevisiae,
pubmed-meshheading:9367739-Saccharomyces cerevisiae Proteins,
pubmed-meshheading:9367739-Tetrahydrofolate Dehydrogenase
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pubmed:year |
1997
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pubmed:articleTitle |
A mutant form of mitochondrial GrpE suppresses the sorting defect caused by an alteration in the presequence of cytochrome b2.
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pubmed:affiliation |
Institut für Biochemie und Molekularbiologie, Universität Freiburg, Germany.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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