Eukaryotic Membranes and Cytoskeleton: Origins and Evolution

CONTENTS PREFACE ............................................................................................................ V 1. THE EARLY EUKARYOTIC FOSSIL RECORD ....................................... 1 Emmanuelle J. Javaux Introduction ......................................................................................................................... 1 The Geological Record ........................................................................................................ 2 Dating Biological Innovations .......................................................................................... 10 Conclusions ........................................................................................................................ 15 2. THE DIVERSITY OF EUKARYOTES AND THE ROOT OF THE EUKARYOTIC TREE......................................................... 20 Henner Brinkmann and Hervé Philippe Woese's Paradigm .............................................................................................................. 20 Progresses in Tree Reconstruction Methods and in Sequencing: The Promise of Phylogenomics ................................................................................. 21 The Root of the Tree of Life .............................................................................................. 25 'Primitive' Eukaryotes: A Second Major Paradigm Shift ............................................ 26 Current Status of the Eukaryotic Phylogeny .................................................................. 27 Molecular Dating ............................................................................................................... 29 From Simple Organism to Simple Processes .................................................................. 31 3. ORIGIN OF EUKARYOTICENDOMEMBRANES: A CRITICAL EVALUATION OF DIFFERENT MODEL SCENARIOS ............... 38 Gáspár Jékely Introduction ....................................................................................................................... 38 Physico-Chemical Constraints of Membrane Topogenesis ............................................ 39 Symbiotic Scenarios for the Origin of the Nucleus and Endomembranes ................... 40 Origin of Endomembranes by de Novo Vesicle Formation ........................................... 44 Autogenous Scenarios ....................................................................................................... 45 Interspecific Interactions at the Origin of Eukaryotic Endomembranes ...................49 xiv Contents 4. ORIGINS AND EVOLUTION OF COTRANSLATIONAL TRANSPORT TO THE ER................................................................. 52 Thomas U. Schwartz Introduction ....................................................................................................................... 52 Mediators of Cotranslational Transport ......................................................................... 53 The Control of Cotranslational Targeting ....................................................................... 55 Evolutionary Considerations ............................................................................................ 57 5. EVOLUTION OF THE ENDOPLASMIC RETICULUM AND THE GOLGI COMPLEX.......................................................... 61 Alexander A. Mironov, Victor V. Banin, Irina S. Sesorova, Viacheslav V. Dolgikh, Alberto Luini and Galina V. Beznoussenko Introduction ....................................................................................................................... 61 Common and Peculiar Features of the