A role of Toc33 in the protochlorophyllide-dependent plastid import pathway of NADPH:proto¬chlorophyllide oxidoreductase (POR) A

Reinbothe, Steffen and Pollmann, Stephan and Springer, Armin and James, Richard Johari and Tichtinsky, Gabrielle and Reinbothe, Christiane (2005). A role of Toc33 in the protochlorophyllide-dependent plastid import pathway of NADPH:proto¬chlorophyllide oxidoreductase (POR) A. "Plant Journal", v. 42 ; pp. 1-12. ISSN 0960-7412. https://doi.org/10.1111/j.1365-313X.2005.02353.x.

Description

Title: A role of Toc33 in the protochlorophyllide-dependent plastid import pathway of NADPH:proto¬chlorophyllide oxidoreductase (POR) A
Author/s:
  • Reinbothe, Steffen
  • Pollmann, Stephan
  • Springer, Armin
  • James, Richard Johari
  • Tichtinsky, Gabrielle
  • Reinbothe, Christiane
Item Type: Article
Título de Revista/Publicación: Plant Journal
Date: 2005
Volume: 42
Subjects:
Freetext Keywords: Arabidopsis, chloroplast biogenesis, protein import, POR, Oep16, Toc33.
Faculty: Centro de Investigación en Biotecnología y Genómica de Plantas (CBGP) (UPM)
Department: Biotecnologia [hasta 2014]
Creative Commons Licenses: Recognition - No derivative works - Non commercial

Full text

[img]
Preview
PDF - Requires a PDF viewer, such as GSview, Xpdf or Adobe Acrobat Reader
Download (2MB) | Preview

Abstract

NADPH: protochlorophyllide oxido reductase (POR) A is a key enzyme of chlorophyll biosynthesis in angiosperms. It is nucleus-encoded, synthesized as a larger precursor in the cytosol and imported into the plastids in a substrate-dependent manner. Plastid envelope membrane proteins, called protochlorophyllide dependent translocon proteins, Ptcs, have been identified that interact with pPORA during import. Amongthem are a 16-kDa ortholog of the previously characterized outer envelope protein Oep16 (named Ptc16) and a33-kDa protein (Ptc33) related to the GTP-binding proteins Toc33 and Toc34 of Arabidopsis. In the present work, we studied the interactions and roles of Ptc16 and Ptc33 during pPORA import. Radio labeled Ptc16/Oep16 was synthesized from a corresponding cDNA and imported into isolated Arabidopsis plastids. Crosslinking experiments revealed that import of35S-Oep16/Ptc16 is stimulated by GTP.35S-Oep16/Ptc16forms larger complexes with Toc33 but not Toc34. Plastids of the ppi1 mutant of Arabidopsis lacking Toc33, were unable to import pPORA in darkness but imported the small subunit precursor of ribulose-1,5-bisphosphate carboxylase/oxygenase (pSSU), precursor ferredoxin (pFd) as well as pPORB which is a close relative of pPORA. In white light, partial suppressions of pSSU, pFd and pPORB import were observed. Our results unveil a hitherto unrecognized role of Toc33 in pPORA import and suggest photo oxidative membrane damage, induced by excess Pchlide accumulating in ppi1 chloroplasts because of the lack of pPORA import, to be the cause of the general drop of protein import.

More information

Item ID: 14044
DC Identifier: http://oa.upm.es/14044/
OAI Identifier: oai:oa.upm.es:14044
DOI: 10.1111/j.1365-313X.2005.02353.x
Official URL: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2005.02353.x/suppinfo
Deposited by: Memoria Investigacion
Deposited on: 20 Dec 2012 13:08
Last Modified: 21 Apr 2016 13:31
  • Logo InvestigaM (UPM)
  • Logo GEOUP4
  • Logo Open Access
  • Open Access
  • Logo Sherpa/Romeo
    Check whether the anglo-saxon journal in which you have published an article allows you to also publish it under open access.
  • Logo Dulcinea
    Check whether the spanish journal in which you have published an article allows you to also publish it under open access.
  • Logo de Recolecta
  • Logo del Observatorio I+D+i UPM
  • Logo de OpenCourseWare UPM