title: Protein translocation into the endoplasmic reticulum (ER)--two similar routes with different modes.
abstract: Protein translocation into the endoplasmic reticulum (ER) occurs cotranslationally with the ribosome tightly bound at the membrane, or post-translationally. Transport of polypeptides is performed by an elaborate structure in the ER membrane consisting of numerous proteins. Both pathways have been reconstituted in vitro using proteoliposomes that contain purified components. Primary structures of these key components have been identified and recent electron microscopic data provide a first impression of the tertiary structure of the translocation apparatus. However, the precise function of most subunits of the translocation apparatus is still a mystery and little is known about structural changes in the translocation site during a transport cycle.
authors.affiliation: Abteilung Biochemie II, Zentrum Biochemie und Molekulare Zellbiologie, Georg-August-Universität Göttingen, Germany.
authors.forename: K U
authors.initials: KU
authors.lastname: Kalies
authors.forename: E
authors.initials: E
authors.lastname: Hartmann
mesh_terms: D001692:Biological Transport / Q000502:physiology; D004721:Endoplasmic Reticulum / Q000502:physiology*; D005057:Eukaryotic Cells / Q000502:physiology; D008565:Membrane Proteins / Q000737:chemistry; D010455:Peptides / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000235:genetics; D021382:Protein Sorting Signals / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D018271:Signal Recognition Particle
chemical_list: D008565:Membrane Proteins; D010455:Peptides; D021382:Protein Sorting Signals; D011506:Proteins; D018271:Signal Recognition Particle