Energy Requirements In Membrane Trafficking

As membrane trafficking research has expanded over the past thirty years, a remarkable convergence of information has been gained by using genetic approaches in yeast cells with biochemical approaches in mammalian cells. This book reflects these advances by devoting one section of the book to yeast cells and the other to mammalian cells, with each section providing both classic and cutting-edge techniques to study macromolecular transport across the membranes.

Membrane traffic is a broad field that studies the complex exchange of membranes that occurs inside the cell. Protein, lipids and other molecules traffic among intracellular organelles, and are delivered to, or transported from the cell surface by virtue of membranous carriers generally referred as "transport intermediates". These carriers have different shapes and sizes, and their biogenesis, modality of transport, and delivery to the final destination are regulated by a multitude of very complex molecular machineries. A concept that has clearly emerged in the last decade is that each membrane pathway does not represent a close system, but is fully integrated with all the other trafficking pathways. The aim of this book is to provide a general overview of the extent of this crosstalk.

Free energy constitutes the most important thermodynamic quantity to understand how chemical species recognize each other, associate or react. Examples of problems in which knowledge of the underlying free energy behaviour is required, include conformational equilibria and molecular association, partitioning between immiscible liquids, receptor-drug interaction, protein-protein and protein-DNA association, and protein stability. This volume sets out to present a coherent and comprehensive account of the concepts that underlie different approaches devised for the determination of free energies. The reader will gain the necessary insight into the theoretical and computational foundations of the subject and will be presented with relevant applications from molecular-level modelling and simulations of chemical and biological systems. Both formally accurate and approximate methods are covered using both classical and quantum mechanical descriptions. A central theme of the book is that the wide variety of free energy calculation techniques available today can be understood as different implementations of a few basic principles. The book is aimed at a broad readership of graduate students and researchers having a background in chemistry, physics, engineering and physical biology.

"Ypt/Rab GTPases form the largest branch of the Ras-related small GTPase superfamily and regulate intracellular membrane trafficking in all eukaryotes. Since their discovery over two decades ago, a wealth of information has accumulated about the roles that"

Membrane proteins are essential determinants of many biological processes in plants. They function in metabolic processes, signal transduction, transport of small molecules and polymers across endo- and plasma membranes, and intercompartmental trafficking of proteins, lipids, and cell wall components. During these integrative processes, dynamic interactions of membrane proteins with other membrane or soluble components are thought to provide a high degree of flexibility that usually characterizes higher plants. This concept is supported by the recent release of a first, partial Arabidopsis interactome by the Arabidopsis Interactome Mapping Consortium (http://www.sciencemag.org/content/333/6042/601.full.htm). The Arabidopsis interactome reveals a strong enrichment of a few network communities, including those for transmembrane transport and vesicle trafficking. Strikingly, the large transmembrane transport community shares a high amount of proteins with the vesicle trafficking community suggesting a strong physical and functional overlap and interaction.