Dissecting Stop Transfer versus Conservative Sorting Pathways for Mitochondrial Inner Membrane Proteins in Vivo
| Autor: | Marie Österberg, Salomé Calado Botelho, Joon-Ki Hong, Hyun Kim, Kwangjin Park |
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| Rok vydání: | 2013 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Molecular Sequence Data Saccharomyces cerevisiae Biology medicine.disease_cause Biochemistry Mitochondrial Proteins GTP-Binding Proteins Membrane Biology Protein targeting medicine Inner membrane Amino Acid Sequence Inner mitochondrial membrane Molecular Biology Membrane Proteins Cell Biology Membrane transport Recombinant Proteins Transmembrane protein Mitochondria Cell biology Transport protein Protein Transport Cellular Microenvironment Membrane protein Mitochondrial Membranes Translocase of the inner membrane Hydrophobic and Hydrophilic Interactions |
| Zdroj: | Journal of Biological Chemistry. 288:1521-1532 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m112.409748 |
| Popis: | Mitochondrial inner membrane proteins that carry an N-terminal presequence are sorted by one of two pathways: stop transfer or conservative sorting. However, the sorting pathway is known for only a small number of proteins, in part due to the lack of robust experimental tools with which to study. Here we present an approach that facilitates determination of inner membrane protein sorting pathways in vivo by fusing a mitochondrial inner membrane protein to the C-terminal part of Mgm1p containing the rhomboid cleavage region. We validated the Mgm1 fusion approach using a set of proteins for which the sorting pathway is known, and determined sorting pathways of inner membrane proteins for which the sorting mode was previously uncharacterized. For Sdh4p, a multispanning membrane protein, our results suggest that both conservative sorting and stop transfer mechanisms are required for insertion. Furthermore, the sorting process of Mgm1 fusion proteins was analyzed under different growth conditions and yeast mutant strains that were defective in the import motor or the m-AAA protease function. Our results show that the sorting of mitochondrial proteins carrying moderately hydrophobic transmembrane segments is sensitive to cellular conditions, implying that mitochondrial import and membrane sorting in the physiological environment may be dynamically tuned. |
| Databáze: | OpenAIRE |
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