Open AccessCyclophilin 20 Is Involved in Mitochondrial Protein Folding in Cooperation with Molecular Chaperones Hsp70 and Hsp60
Author(s) -
Joachim Rassow,
Katja Mohrs,
Stefanie Koidl,
Ilse B. Barthelmess,
Nikolaus Pfanner,
Maximilian Tropschug
Publication year - 1995
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.15.5.2654
Subject(s) - biology , co chaperone , hsp60 , cyclophilin , protein folding , chaperone (clinical) , hsp70 , cyclophilin a , peptidylprolyl isomerase , heat shock protein , folding (dsp implementation) , chaperonin , microbiology and biotechnology , biochemistry , enzyme , isomerase , gene , medicine , pathology , engineering , electrical engineering
We studied the role of mitochondrial cyclophilin 20 (CyP20), a peptidyl-prolyl cis-trans isomerase, in preprotein translocation across the mitochondrial membranes and protein folding inside the organelle. The inhibitory drug cyclosporin A did not impair membrane translocation of preproteins, but it delayed the folding of an imported protein in wild-type mitochondria. Similarly, Neurospora crassa mitochondria lacking CyP20 efficiently imported preproteins into the matrix, but folding of an imported protein was significantly delayed, indicating that CyP20 is involved in protein folding in the matrix. The slow folding in the mutant mitochondria was not inhibited by cyclosporin A. Folding intermediates of precursor molecules reversibly accumulated at the molecular chaperones Hsp70 and Hsp60 in the matrix. We conclude that CyP20 is a component of the mitochondrial protein folding machinery and that it cooperates with Hsp70 and Hsp60. It is speculated that peptidyl-prolyl cis-trans isomerases in other cellular compartments may similarly promote protein folding in cooperation with chaperone proteins.