Protein Targeting to Mitochondria (Volume 17) (Advances in Molecular and Cell Biology, Volume 17)

A large number of newly-synthesized polypeptides must cross one or several intracellular membranes to reach their functional locations in the eukaryotic cell. The mechanisms of protein trafficking, in particular the post-translational targeting and membrane translocation of proteins, are of fundamental biological importance and are the focus of intensive research world-wide. For more than 15 years, mitochondria have served as the paradigm organelle system to study these processes. Although key questions, such as how precisely proteins cross a membrane, still remain to be answered, exciting progress has been made in understanding the basic pathways of protein import into mitochondria and the components involved. In addition to a fascinating richness and complexity in detail, the analysis of mitochondrial protein import has revealed mechanistic principles of general significance: Major discoveries include the demonstration of the requirement of an unfolded state for translocation and of the essential role of molecular chaperones on both sides of the membranes in maintaining a translocation-competent conformation and in protein folding after import. It is becoming clear how a polypeptide chain is "reeled" across the membrane in an ATP-dependent process by the functional cooperation of membrane proteins, presumably constituting part of a transmembrane channel, with peripheral components at the trans-side of the membrane. In this volume, eminent experts in the field take the time to review the central aspects of mitochondrial biogenesis. The logical order of the 16 chapters is determined by the sequence of steps during protein import, starting with the events taking place in the cytosol, followed by the recognition of targeting signals, the translocation of precursor proteins across the outer and inner membranes, their proteolytic processing and intramitochondrial sorting, and finally their folding and oligomeric assembly. In addition, the mechanisms involved in the export of mitochondrially encoded proteins as well as recent advances in understanding the division and inheritance of mitochondria will be discussed. Content: Edited By Page iii Copyright page Page iv List of Contributors Pages ix-xii Preface Pages xiii-xiv F. Ulrich Hart Targeting Signals for Protein Import into Mitochondria and Other Subcellular Organelles Original Research Article Pages 1-12 Gunnar von Heijne Protein Transport into Mitochondria: Cytosolic Factors Which Operate During and After Translation in Protein Trafficking Original Research Article Pages 13-32 Lisa Estey, Michael G. Douglas Presequence Binding Proteins as Cytosolic Import-Stimulation Factors in Mitochondrial Protein Import Original Research Article Pages 33-49 Katsuyoshi Mihara, Tsuneo Omura Molecular Mechanisms of Protein Translocation into and Across the Mitochondrial Outer Membrane Original Research Article Pages 51-70 Roland Lill, Andreas Mayer, Harald Steiner, Gyula Kispal, Walter Neupert Targeting and Insertion of Proteins into the Mitochondrial Outer Membrane Original Research Article Pages 71-80 Gordon C. Shore, Heidi M. McBride, Douglas G. Millar, Nancy A.E. Steenaart, Mai Nguyen Targeting and Translocation of Preproteins by the Toms of the Mitochondrial Receptor Complex Original Research Article Pages 81-102 Petra Keil, Angelika Hönlinger, Nikolaus Pfanner Mitochondrial Import of Cytochrome C Original Research Article Pages 103-126 Mark E. Dumont Translocation of Preproteins Across the Mitochondrial Inner Membrane: Tims and HSP70 Original Research Article Pages 127-148 Michiel Meijer, Ammy Maarse, Michael KüBbrich, Nikolaus Pfanner Unraveling the Protein Translocation Machinery in the Mitochondrial Inner Membrane Original Research Article Pages 149-162 Nafsika G. Kronidou, Martin Horst Proteolytic Processing of Mitochondrial Precursor Proteins Original Research Article Pages 163-191 Wayne A. Fenton, Frantisek Kalousek Sorting of Proteins to the Mitochondrial Intermembrane Space Original Research Article Pages 193-220 Rosemary A. Stuart, Heike Fölsch, Albrecht Gruhler, Walter Neupert Energetics of Mitochondrial Protein Import and Intramitochondrial Protein Sorting Original Research Article Pages 221-245 Sabine Rospert Export of Proteins from Mitochondria Original Research Article Pages 247-280 Robert O. Poyton, Kevin A. Sevarino, Edward E. McKee, David J.M. Duhl, Vicki Cameron, Bradley Goehring Protein Folding in Mitochondria Original Research Article Pages 281-297 Jörg Höhfeld Assembly of Multisubunit Complexes in Mitochondria Original Research Article Pages 299-339 Mark Prescott, Rodney J. Devenish, Phillip Nagley The Division and Inheritance of Mitochondria Original Research Article Pages 341-350 Michael P. Yaffe Index Pages 351-356