Mitochondrial Heat Shock Protein (Hsp) 70 and Hsp10 Cooperate in the Formation of Hsp60 Complexes |
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| Authors: | Lena B?ttinger Silke Oeljeklaus Bernard Guiard Sabine Rospert Bettina Warscheid Thomas Becker |
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| Affiliation: | From the ‡Institut für Biochemie und Molekularbiologie, ZBMZ.;the §Fakultät für Biologie.;¶Institut für Biologie II, Abteilung Biochemie und Funktionelle Proteomik, Universität Freiburg, 79104 Freiburg, Germany.;the ‖BIOSS Centre for Biological Signalling Studies, and ;the **Centre de Génétique Moléculaire, CNRS, 91190 Gif-sur-Yvette, France |
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| Abstract: | Mitochondrial Hsp70 (mtHsp70) mediates essential functions for mitochondrial biogenesis, like import and folding of proteins. In these processes, the chaperone cooperates with cochaperones, the presequence translocase, and other chaperone systems. The chaperonin Hsp60, together with its cofactor Hsp10, catalyzes folding of a subset of mtHsp70 client proteins. Hsp60 forms heptameric ring structures that provide a cavity for protein folding. How the Hsp60 rings are assembled is poorly understood. In a comprehensive interaction study, we found that mtHsp70 associates with Hsp60 and Hsp10. Surprisingly, mtHsp70 interacts with Hsp10 independently of Hsp60. The mtHsp70-Hsp10 complex binds to the unassembled Hsp60 precursor to promote its assembly into mature Hsp60 complexes. We conclude that coupling to Hsp10 recruits mtHsp70 to mediate the biogenesis of the heptameric Hsp60 rings. |
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| Keywords: | 70-kDa Heat Shock Protein (Hsp70) Mitochondria Molecular Chaperone Protein Assembly Protein Folding Hsp10 Hsp60 Protein Biogenesis |
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