New mechanistic insights into pre-protein transport across the second outermost plastid membrane of diatoms.

Item request has been placed! ×
Item request cannot be made. ×
loading   Processing Request
Read More Add to Saved list
  • Author(s): Hempel F;Hempel F; Felsner G; Maier UG
  • Source:
    Molecular microbiology [Mol Microbiol] 2010 May; Vol. 76 (3), pp. 793-801. Date of Electronic Publication: 2010 Mar 25.
  • Publication Type:
    Journal Article; Research Support, Non-U.S. Gov't
  • Language:
    English
  • Additional Information
    • Source:
      Publisher: Blackwell Scientific Publications Country of Publication: England NLM ID: 8712028 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1365-2958 (Electronic) Linking ISSN: 0950382X NLM ISO Abbreviation: Mol Microbiol Subsets: MEDLINE
    • Publication Information:
      Original Publication: Oxford, OX ; Boston, MA : Blackwell Scientific Publications, c1987-
    • Subject Terms:
      Algal Proteins/*metabolism ; Diatoms/*metabolism ; Intracellular Membranes/*metabolism ; Plastids/*metabolism; Algal Proteins/genetics ; Diatoms/genetics ; Plastids/genetics ; Protein Transport
    • Abstract:
      Chromalveolates like the diatom Phaeodactylum tricornutum arose through the uptake of a red alga by a phagotrophic protist, a process termed secondary endosymbiosis. In consequence, the plastids are surrounded by two additional membranes compared with primary plastids. This plastid morphology poses additional barriers for plastid-destined proteins, which are mostly nucleus-encoded. Recent investigations have focused on the postulated translocon of the second outermost membrane (periplastidal membrane, PPM). These studies identified a symbiont-specific ERAD (endoplasmic reticulum-associated degradation)-like machinery (SELMA), which has been implicated in plastid pre-protein import. Despite this recent progress, key factors for protein transport via SELMA are still unknown. As SELMA substrates presumably undergo ubiquitination, a corresponding ubiquitin ligase and an enzyme for the subsequent removal of ubiquitin need to reside in the space between the second and third membrane (periplastidal compartment, PPC). Here we characterize two proteins fulfilling these criteria. We show that ptE3P (P.t ricornutumE3 enzyme of the PPC), the ubiquitin ligase, and ptDUP (P.t ricornutumde-ubiquitinating enzyme of the PPC), the de-ubiquitinase, localize to the PPM and PPC, respectively. In addition, we demonstrate their retained functionality by in vitro data.
    • Accession Number:
      0 (Algal Proteins)
    • Publication Date:
      Date Created: 20100330 Date Completed: 20100927 Latest Revision: 20100615
    • Publication Date:
      20231215
    • Accession Number:
      10.1111/j.1365-2958.2010.07142.x
    • Accession Number:
      20345650