Kessler, Félix

2020-1-31, Kessler, Félix

Heme plays an active role in primary plant metabolic pathways as well as in stress signaling. In this study, we characterized the predicted heme-binding protein SOUL4. Proteomics evidence suggests that SOUL4 is a component of Arabidopsis plastoglobules (PGs, chloroplast lipid droplets). SOUL4 contains heme-binding motifs and the recombinant protein is shown here to bind heme in vitro. Fluorescence-tagged SOUL4 colocalized with the specific PG marker Fibrillin1A (FBN1A) in transiently transformed Nicotiana benthamiana leaves. In addition, SOUL4 cofractionated with another PG marker Fibrillin2 (FBN2) in sucrose gradient ultracentrifugation experiments. In vitro kinase experiments revealed that SOUL4 is phosphorylated by a yet unknown chloroplast protein kinase. Our data demonstrate that SOUL4 is a bona fide PG protein and may function in heme-buffering in the chloroplast.

2014, Martinis, Jacopo, Glauser, Gaëtan, Valimareanu, Sergiu, Stettler, Michaela, Zeeman, Samuel C, Yamamoto, Hiroshi, Shikanai, Toshiharu, Kessler, Félix

2013, Shanmugabalaji, Venkatasalam, Besagni, Celine, Eugeni Piller, Lucia, Douet, Véronique, Ruf, Stephanie, Bock, Ralph, Kessler, Félix

2012, Eugeni Piller, Lucia, Abraham, Marion, Dörmann, Peter, Kessler, Félix, Besagni, Celine

2019-10-15, Kessler, Félix, Longoni, Fiamma

A genetic screen has identified the first signaling component of the unfolded protein response in chloroplasts.

2014, Kessler, Félix, Glauser, Gaëtan

2012, Sakuraba, Yasuhito, Schelbert, Silvia, Park, So-Yon, Han, Su-Hyun, Lee, Byoung-Doo, Andrès, Céline Besagni, Kessler, Félix, Hörtensteiner, Stefan, Paek, Nam-Chon

2019-6-20, Pralon, Thibaut, Venkatasalam, Shanmugabalaji, Longoni, Fiamma, Ksas, Brigitte, Collombat, Joy, Desmeules, Saskia, Glauser, Gaëtan, Havaux, Michel, Finazzi, Giovanni, Kessler, Félix

Photosynthesis produces organic carbon via a light-driven electron flow from H2O to CO2 that passes through a pool of plastoquinone molecules. These molecules are either present in the photosynthetic thylakoid membranes, participating in photochemistry (photoactive pool), or stored (non-photoactive pool) in thylakoid-attached lipid droplets, the plastoglobules. The photoactive pool acts also as a signal of photosynthetic activity allowing the adaptation to changes in light condition. Here we show that, in Arabidopsis thaliana, proton gradient regulation 6 (PGR6), a predicted atypical kinase located at plastoglobules, is required for plastoquinone homoeostasis, i.e. to maintain the photoactive plastoquinone pool. In a pgr6 mutant, the photoactive pool is depleted and becomes limiting under high light, affecting short-term acclimation and photosynthetic efficiency. In the long term, pgr6 seedlings fail to adapt to high light and develop a conditional variegated leaf phenotype. Therefore, PGR6 activity, by regulating plastoquinone homoeostasis, is required to cope with high light.

2013, Besagni, Celine, Kessler, Félix

2012, Lippold, Felix, vom Dorp, Katharina, Abraham, Marion, Hölzl, Georg, Wewer, Vera, Yilmaz, Jenny Lindberg, Lager, Ida, Montandon, Cyrille, Besagni, Celine, Kessler, Félix