This book deals with the molecular mechanisms of membrane trafficking, a central eukaryotic cell biological process. In the post-genomic era many essential molecules involved in intracellular membrane/protein transport are emerging. A huge task now is to compile the molecular networks that govern these processes. Understanding of regulatory processes and participating molecules are likely to reveal global cellular regulatory circuits that couple membrane trafficking with other cellular functions. Such cell biological features are only starting to emerge. This book puts special emphasis on such mechanisms and processes. The contents discusses the role of coat proteins, tethering complexes, small rab GTPases, Sec1-family proteins and SNARE molecule phosphorylation in exocytosis, endocytosis and membrane fusion. In addition, the role of lipids in vesicle formation and membrane fusion, and some specialized cell biological denovo membrane generation processes are discussed.