rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Investigating cotranslational integration of a multi-spanning membrane protein into the endoplasmic reticulum membrane
  name:
    name part: Jongsma, Candice Gene.
    role:
      role term: creator
  name:
    name part: Johnson, Arthur E.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2010
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: electronic
    form: remote
    extent: 1 online resource.
  abstract: Most membrane proteins in eukaryotic cells are co-translationally integrated into the endoplasmic reticulum (ER) membrane at aqueous pores termed translocons. During multi-spanning membrane protein (MSMP) integration, the nascent polypeptide is threaded into the translocon pore where each successive transmembrane segment (TMS) is moved laterally through the translocon into the bilayer. The hydrophilic polypeptide segments on each side of the TMS are alternately directed into either the aqueous cytosol or the aqueous ER lumen. How is the ER membrane permeability barrier maintained during this process? For a single-spanning signal-cleaved membrane protein, nascent chain movement into the lumen occurs while an ion-tight ribosome-translocon junction prevents ion flow through the translocon pore. Prior to opening this junction to allow nascent chain movement into the cytosol, BiP (Hsp70 binding protein) effects closure at the lumenal end of the pore to maintain the membrane permeability barrier. To determine whether the ribosome and BiP alternately mediate pore closure during the integration of a MSMP, integration intermediates with nascent chains of different lengths were prepared with a fluorescent probe positioned in the nascent chain far inside the ribosomal tunnel. Nascent chain exposure to the cytosol or lumen was then detected by the collisional quenching of the probe by iodide ions located on either the cytosolic or lumenal side of the membrane. While the first TMS through the tunnel caused the ribosome-translocon junction to open, the second TMS elicited both the closure of this junction and the opening of the lumenal end of the pore. Movement of a third TMS through the tunnel caused the ribosome-translocon junction to re-open after closure of the lumenal end. Pore opening and closing occurred after each TMS was 4-7 residues from the peptidyltransferase center, irrespective of TMS location in the nascent chain. The ribosome treated all TMSs in the same manner, r…
  note: by Candice Gene Jongsma.
  note: "Major Subject: Chemistry"
  note: Title from author supplied metadata (automated record created 2010-03-12 12:08:51).
  note: Electronic resource.
  note: Doctor of Philosophy Texas A&M University 2008 http://hdl.handle.net/1969.1/ETD-TAMU-2894
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major chemistry
  subject:
    topic: PROTEIN
  subject:
    topic: FLUORESCENCE
  subject:
    topic: MEMBRANE
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-2894
  record info:
    record content source: TXA
    record creation date: 100426
    record change date: 20151201120110.0
    record identifier: in00002582189