Université de Neuchâtel

The Acidic A-Domain of Arabidopsis Toc159 Occurs as a Hyperphosphorylated Protein

Agne, Birgit ; Andrès, Charles ; Montandon, Cyril ; Christ, Bastien ; Ertan, Anouk ; Jung, Friederike ; Infanger, Sibylle ; Bischof, Sylvain ; Baginsky, Sacha ; Kessler, Felix

In: Plant Physiology, 2010, vol. 53, no. 3, p. 1016-1030

The translocon at the outer membrane of the chloroplast assists the import of a large class of preproteins with amino-terminal transit sequences. The preprotein receptors Toc159 and Toc33 in Arabidopsis (Arabidopsis thaliana) are specific for the accumulation of abundant photosynthetic proteins. The receptors are homologous GTPases known to be regulated by phosphorylation within their...

Université de Neuchâtel

Characterization of Chloroplast Protein Import without Tic56, a Component of the 1-Megadalton Translocon at the Inner Envelope Membrane of Chloroplasts

Köhler, Daniel ; Montandon, Cyril ; Hause, Gerd ; Majovsky, Petra ; Kessler, Felix ; Baginsky, Sacha ; Agne, Birgit

In: Plant Physiology, 2015, vol. 167, no. 3, p. 972-990

We report on the characterization of Tic56, a unique component of the recently identified 1-MD translocon at the inner envelope membrane of chloroplasts (TIC) in Arabidopsis (Arabidopsis thaliana) comprising Tic20, Tic100, and Tic214. We isolated Tic56 by copurification with Tandem Affinity Purification-tagged Toc159 in the absence of precursor protein, indicating spontaneous and...

Université de Neuchâtel

The Chloroplast Import Receptor Toc90 Partially Restores the Accumulation of Toc159 Client Proteins in the Arabidopsis thaliana ppi2 Mutant

Infanger, Sibylle ; Bischof, Sylvain ; Hiltbrunner, Andreas ; Agne, Birgit ; Baginsky, Sacha ; Kessler, Felix

In: Molecular Plant, 2011, vol. 4, no. 2, p. 252–263

Successful import of hundreds of nucleus-encoded proteins is essential for chloroplast biogenesis. The import of cytosolic precursor proteins relies on the Toc- (translocon at the outer chloroplast membrane) and Tic- (translocon at the inner chloroplast membrane) complexes. In Arabidopsis thaliana, precursor recognition is mainly mediated by outer membrane receptors belonging to two...

Université de Neuchâtel

The Novel Chloroplast Outer Membrane Kinase KOC1 Is a Required Component of the Plastid Protein Import Machinery

Zufferey, Mónica ; Montandon, Cyrille ; Douet, Véronique ; Demarsy, Emilie ; Agne, Birgit ; Baginsky, Sacha ; Kessler, Felix

In: Journal of biological chemistry, 2017, vol. 292, no. 17, p. 6952-6964

The biogenesis and maintenance of cell organelles such as mitochondria and chloroplasts require the import of many proteins from the cytosol, a process that is controlled by phosphorylation. In the case of chloroplasts, the import of hundreds of different proteins depends on translocons at the outer and inner chloroplast membrane (TOC and TIC, respectively) complexes. The essential protein TOC159...

Université de Neuchâtel

Plastid Proteome Assembly without Toc159: Photosynthetic Protein Import and Accumulation of N-Acetylated Plastid Precursor Proteins

Bischof, Sylvain ; Baerenfaller, Katja ; Wildhaber, Thomas ; Troesch, Raphael ; Vidi, Pierre-Alexandre ; Roschitzki, Bernd ; Hirsch-Hoffmann, Matthias ; Hennig, Lars ; Kessler, Felix ; Gruissem, Wilhelm ; Baginsky, Sacha

In: The Plant Cell, 2011, vol. 23, no. 11, p. 3911-3928

Import of nuclear-encoded precursor proteins from the cytosol is an essential step in chloroplast biogenesis that is mediated by protein translocon complexes at the inner and outer envelope membrane (TOC). Toc159 is thought to be the main receptor for photosynthetic proteins, but lacking a large-scale systems approach, this hypothesis has only been tested for a handful of photosynthetic and...

Université de Neuchâtel

Tocopherol Cyclase (VTE1) Localization and Vitamin E Accumulation in Chloroplast Plastoglobule Lipoprotein Particles

Vidi, Pierre-Alexandre ; Kanwischer, Marion ; Baginsky, Sacha ; Austin, Jotham R. ; Csucs, Gabor ; Dörmann, Peter ; Kessler, Felix ; Bréhélin, Claire

In: The Journal of Biological Chemistry, 2006, vol. 281, p. 11225-11234

Chloroplasts contain lipoprotein particles termed plastoglobules. Plastoglobules are generally believed to have little function beyond lipid storage. Here we report on the identification of plastoglobule proteins using mass spectrometry methods in Arabidopsis thaliana. We demonstrate specific plastoglobule association of members of the plastid lipid-associated proteins/fibrillin family as...