Characterization of a Plastoglobule-Localized SOUL4 Heme-Binding Protein in Arabidopsis thaliana.
- Shanmugabalaji V Laboratory of Plant Physiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
- Grimm B Institute of Biology/Plant Physiology, Humboldt University Berlin, Berlin, Germany.
- Kessler F Laboratory of Plant Physiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
- 2020-02-21
Published in:
- Frontiers in plant science. - 2020
English
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.
- Language
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- English
- Open access status
- gold
- Identifiers
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- DOI 10.3389/fpls.2020.00002
- PMID 32076429
- Persistent URL
- https://sonar.ch/global/documents/291222
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