Mrs2p is an essential component of the major electrophoretic Mg2+ influx system in mitochondria.
In: The EMBO journal, Jg. 22 (2003-03-17), Heft 6, S. 1235-44
academicJournal
Zugriff:
Steady-state concentrations of mitochondrial Mg(2+) previously have been shown to vary with the expression of Mrs2p, a component of the inner mitochondrial membrane with two transmembrane domains. While its structural and functional similarity to the bacterial Mg(2+) transport protein CorA suggested a role for Mrs2p in Mg(2+) influx into the organelle, other functions in cation homeostasis could not be excluded. Making use of the fluorescent dye mag-fura 2 to measure free Mg(2+) concentrations continuously, we describe here a high capacity, rapid Mg(2+) influx system in isolated yeast mitochondria, driven by the mitochondrial membrane potential Deltapsi and inhibited by cobalt(III)hexaammine. Overexpression of Mrs2p increases influx rates 5-fold, while the deletion of the MRS2 gene abolishes this high capacity Mg(2+) influx. Mg(2+) efflux from isolated mitochondria, observed with low Deltapsi only, also requires the presence of Mrs2p. Cross-linking experiments revealed the presence of Mrs2p-containing complexes in the mitochondrial membrane, probably constituting Mrs2p homo- oligomers. Taken together, these findings characterize Mrs2p as the first molecularly identified metal ion channel protein in the inner mitochondrial membrane.
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Mrs2p is an essential component of the major electrophoretic Mg2+ influx system in mitochondria.
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Autor/in / Beteiligte Person: | Kolisek, M ; Zsurka, G ; Samaj, J ; Weghuber, J ; Schweyen, RJ ; Schweigel, M |
Zeitschrift: | The EMBO journal, Jg. 22 (2003-03-17), Heft 6, S. 1235-44 |
Veröffentlichung: | 2024- : [London] : Nature Publishing Group ; <i>Original Publication</i>: Eynsham, Oxford, England : Published for the European Molecular Biology Organization by IRL Press, [c1982-, 2003 |
Medientyp: | academicJournal |
ISSN: | 0261-4189 (print) |
DOI: | 10.1093/emboj/cdg122 |
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