title: Different effects of Sec61α, Sec62 and Sec63 depletion on transport of polypeptides into the endoplasmic reticulum of mammalian cells.
abstract: Co-translational transport of polypeptides into the endoplasmic reticulum (ER) involves the Sec61 channel and additional components such as the ER lumenal Hsp70 BiP and its membrane-resident co-chaperone Sec63p in yeast. We investigated whether silencing the SEC61A1 gene in human cells affects co- and post-translational transport of presecretory proteins into the ER and post-translational membrane integration of tail-anchored proteins. Although silencing the SEC61A1 gene in HeLa cells inhibited co- and post-translational transport of signal-peptide-containing precursor proteins into the ER of semi-permeabilized cells, silencing the SEC61A1 gene did not affect transport of various types of tail-anchored protein. Furthermore, we demonstrated, with a similar knockdown approach, a precursor-specific involvement of mammalian Sec63 in the initial phase of co-translational protein transport into the ER. By contrast, silencing the SEC62 gene inhibited only post-translational transport of a signal-peptide-containing precursor protein.
authors.affiliation: Medical Biochemistry and Molecular Biology, Saarland University, Homburg, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Lang
authors.forename: Julia
authors.initials: J
authors.lastname: Benedix
authors.forename: Sorin V
authors.initials: SV
authors.lastname: Fedeles
authors.forename: Stefan
authors.initials: S
authors.lastname: Schorr
authors.forename: Claudia
authors.initials: C
authors.lastname: Schirra
authors.forename: Nico
authors.initials: N
authors.lastname: Schäuble
authors.forename: Carolin
authors.initials: C
authors.lastname: Jalal
authors.forename: Markus
authors.initials: M
authors.lastname: Greiner
authors.forename: Sarah
authors.initials: S
authors.lastname: Hassdenteufel
authors.forename: Jörg
authors.initials: J
authors.lastname: Tatzelt
authors.forename: Birgit
authors.initials: B
authors.lastname: Kreutzer
authors.forename: Ludwig
authors.initials: L
authors.lastname: Edelmann
authors.forename: Elmar
authors.initials: E
authors.lastname: Krause
authors.forename: Jens
authors.initials: J
authors.lastname: Rettig
authors.forename: Stefan
authors.initials: S
authors.lastname: Somlo
authors.forename: Richard
authors.initials: R
authors.lastname: Zimmermann
authors.forename: Johanna
authors.initials: J
authors.lastname: Dudek
mesh_terms: D000818:Animals; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018832:Molecular Chaperones; D041681:NIH 3T3 Cells; D010455:Peptides / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D016601:RNA-Binding Proteins; D000069816:SEC Translocation Channels
chemical_list: D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D018832:Molecular Chaperones; D010455:Peptides; D011498:Protein Precursors; D016601:RNA-Binding Proteins; D000069816:SEC Translocation Channels; C000613244:SEC61A1 protein, human; C577653:SEC61A1 protein, mouse; C103676:SEC62 protein, human; C577651:SEC62 protein, mouse; C487464:SEC63 protein, human; C577652:SEC63 protein, mouse; D004265:DNA Helicases