Chloroplast biogenesis and protein quality control

Research focus

Chloroplasts are a crucial component of our planet’s life-support system: they sequester carbon dioxide and release oxygen while transforming solar energy into chemical energy during a process commonly known as photosynthesis. Chloroplasts have a fascinating evolutionary history and are a marvellous example of the relationship between structure and function. They contain a highly organized system of membranes where chemical reactions take place with remarkable precision. These reactions are orchestrated by multiprotein complexes whose subunits are often encoded by the physically separated chloroplast and nuclear genomes.

Our lab aims to investigate the core machines and the signaling pathways involved in chloroplast biogenesis and protein quality control. With our work, we envision answering fundamental questions in biology while developing or applying innovative research tools.

Currently, we are seeking a molecular understanding of the chloroplast unfolded protein response, a signalling pathway that allows photosynthetic eukaryotes to sense the accumulation of damaged proteins in their chloroplasts and mitigate the resulting stress by reprogramming nuclear gene expression.

We employ two complementary model organisms for our studies: Chlamydomonas reinhardtii, a tiny, single-celled, photosynthetic eukaryote, where we can combine biochemical and genetic approaches with the power of high-throughput robotics, and Arabidopsis thaliana, a land plant where we can explore how intracellular signaling pathways have been shaped during evolution to meet the specific developmental needs of multicellular organisms.

We are driven by curiosity and imagination, and we celebrate creative diversity.

 

Selected publications

Fauser F, Vilarrasa-Blasi J, Onishi M, et al. (2022) Systematic characterization of gene function in the photosynthetic alga Chlamydomonas reinhardtii. Nat Genet 54(5):705-14bioRxiv:2020.12.11.42095.

Ramundo S, Asakura Y, Salomé PA, et al. (2020) Coexpressed subunits of dual genetic origin define a conserved supercomplex mediating essential protein import into chloroplasts. Proc Natl Acad Sci U S A.

Perlaza K, Toutkoushian H, Boone M, et al. (2019) The Mars1 kinase confers photoprotection through signaling in the chloroplast unfolded protein response. eLife.

Ramundo S, Casero D, Mühlhaus T, et al. (2014) Conditional Depletion of the Chlamydomonas Chloroplast ClpP Protease Activates Nuclear Genes Involved in Autophagy and Plastid Protein Quality Control. Plant Cell.

Ramundo S, Rahire M, Schaad O, et al. (2013) Repression of essential chloroplast genes reveals new signaling pathways and regulatory feedback loops in chlamydomonas. Plant Cell.

 

Group Leader


PhD Student


Senior Research Assistant