Contents. List of Contributors. The Nuclear Pore Complex: Toward its Molecular Architecture, Structure, and Function (N. Panté and U. Aebi). Structure and Function of Mitochondrial Presequences (M. Maduke and D. Roise). Bacterial Toxin Transport: The Hemolysin System (J.A. Sheps, F. Zhang, and V. Ling). Protein Sorting to the Yeast Vacuole (B.F. Horazdovsky, J.H. Stack, and S.D. Emr). Bacterial Extracellular Secretion: Transport of a-Lytic Protease Across the Outer Membrane of Escherichia Coli (A.F. Boggs and D.A. Agard). Mechanisms of Peroxisome Biogenesis: Regulation of Peroxisomal Enzymes, and their Subsequent Sorting to Peroxisomes (G.M. Small). Peroxisomal Topogenic Signals and the Etiology of Peroxisome-Deficient Disease (U. Fujiki). ATP Binding Cassette Proteins in Yeast (C. Berkower and S. Michaelis). Membrane Protein Transport in Eukaryotic Secretion Cells (K.K. Goncz and S.S. Rothman). Index.