title: The α-helical structure of prodomains promotes translocation of intrinsically disordered neuropeptide hormones into the endoplasmic reticulum.
abstract: Different neuropeptide hormones, which are either too small to adopt a stable conformation or are predicted to be intrinsically disordered, are synthesized as larger precursors containing a prodomain in addition to an N-terminal signal peptide. We analyzed the biogenesis of three unstructured neuropeptide hormones and observed that translocation of these precursors into the lumen of the endoplasmic reticulum (ER) is critically dependent on the presence of the prodomain. The hormone domains could be deleted from the precursors without interfering with ER import and secretion, whereas constructs lacking the prodomain remained in the cytosol. Domain-swapping experiments revealed that the activity of the prodomains to promote productive ER import resides in their ability to adopt an α-helical structure. Removal of the prodomain from the precursor did not interfere with co-translational targeting of the nascent chain to the Sec61 translocon but with its subsequent productive translocation into the ER lumen. Our study reveals a novel function of prodomains to enable import of small or intrinsically disordered secretory proteins into the ER based on their ability to adopt an α-helical conformation.
authors.affiliation: Neurobiochemistry, Adolf Butenandt Institute, Ludwig Maximilians University Munich, 80336 Munich, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Dirndorfer
authors.affiliation: Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany.
authors.forename: Ralf P
authors.initials: RP
authors.lastname: Seidel
authors.affiliation: Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel.
authors.forename: Guy
authors.initials: G
authors.lastname: Nimrod
authors.affiliation: Neurobiochemistry, Adolf Butenandt Institute, Ludwig Maximilians University Munich, 80336 Munich, Germany.
authors.forename: Margit
authors.initials: M
authors.lastname: Miesbauer
authors.affiliation: Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel.
authors.forename: Nir
authors.initials: N
authors.lastname: Ben-Tal
authors.affiliation: Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Engelhard
authors.affiliation: Medical Biochemistry and Molecular Biology, Saarland University Homburg, 66421 Homburg/Saar, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Zimmermann
authors.affiliation: Neurobiochemistry, Adolf Butenandt Institute, Ludwig Maximilians University Munich, 80336 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 80336 Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), 80336 Munich, Germany.
authors.forename: Konstanze F
authors.initials: KF
authors.lastname: Winklhofer
authors.affiliation: Neurobiochemistry, Adolf Butenandt Institute, Ludwig Maximilians University Munich, 80336 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 80336 Munich, Germany. Electronic address: Joerg.Tatzelt@med.uni-muenchen.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Tatzelt
mesh_terms: D000818:Animals; D002460:Cell Line; D002474:Cell-Free System; D002942:Circular Dichroism; D018076:DNA, Complementary / Q000378:metabolism; D019286:Endopeptidase K / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009479:Neuropeptides / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D021382:Protein Sorting Signals; D017433:Protein Structure, Secondary; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D006728:Hormones; D009479:Neuropeptides; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; D019286:Endopeptidase K
keywords: Endoplasmic Reticulum (ER); Intrinsically Disordered Proteins; Neuropeptide; Neuroscience; Protein Folding