A multidisciplinary approach to investigate cell growth and division in archaea with a pseudomurein cell wall
The Archaea have recently come to center stage, not only because of their key role in the origin of eukaryotes (1), but also as important yet neglected residents of the human microbiome (2).
We have recently developed the first experimental model of a host-associated archaeon, Methanobrevibacter smithii, the main species of methanogens from the human gut. We have demonstrated that M. smithii is an ovococcoid that divides binarily using a homologue of FtsZ and its anchor SepF (3). Interestingly, while most archaea contain a proteinaceous S-layer as major component of the cell envelope, M. smithii and its close relatives possess a cell wall made of pseudopeptidoglycan (pPG). It structurally resembles its bacterial counterpart, but is chemically distinct, indicating an independent evolutionary origin. How these archaea “reinvented” a pPG cell wall, and what were the consequences at the cellular level are fascinating open questions. In fact, the archaeal machineries involved in cell growth and division in the presence of a pPG cell wall remain largely unknown (4).
The project aims at identifying and characterizing additional components of the M. smithii divisome and elongasome and understanding how the cell wall is synthesized and modified during the cell cycle. A wide range of approaches will be used, including immunolabeling and high-resolution microscopy, protein-protein interaction, biochemical characterization, and bioinformatics analysis.
The results obtained will have strong impact on the rapidly expanding field of archaeal cell biology. Moreover, by identifying the elements driving cell growth and division in this major and yet neglected component of the human microbiome, the project will contribute essential information to further research on the role of archaea in health and disease.
Applicants should hold (or expect shortly) a PhD in Life Sciences and a strong background in prokaryotic cell biology and/or biochemistry.
Previous work on Archaea is not mandatory. All the necessary training to work with methanogens will be provided by the lab. Previous experience with sequence analysis is a plus, but also not strictly necessary, as all members of the group are encouraged to acquire expertise through training either by staff bioinformaticians or frequent classes at Institut Pasteur.
The successful candidate will join the group “Evolutionary Biology of the Microbial Cell” headed by Professor Simonetta Gribaldo at the Department of Microbiology (https://research.pasteur.fr/en/team/evolutionary-biology-of-the-microbial-cell/).
We are a highly interdisciplinary team working on large-scale evolution of Bacteria and Archaea, with a strong interest in the cell envelope. We combine different approaches merging in silico analyses (phylogenomics, metagenomics) with wet lab approaches (molecular biology, cell biology, microscopy, biochemistry) to understand major and ancient evolutionary events on the Tree of Life. The group has all the equipment and expertise to grow and manipulate methanogens and many other ongoing lines of research on their evolution, diversity, and role in health and disease. Other than M. smithii, our second experimental model is the bacterium Veillonella parvula, a member of the Firmicutes with an outer membrane. The postdoctoral fellow will therefore be exposed to a wide range of topics and have the possibility to acquire different expertise present in the lab.
The Institute Pasteur is in center Paris and provides state-of-the-art technology with its multiple technical platforms, and full administrative support for foreign candidates.
The position is immediately available and should ideally start not later than Spring 2023. Funding is available for 3 years and can be extended.
Applications should be sent to simonetta.gribaldo(at)pasteur.fr and include a full CV and motivation letter, as well as two references.
- Adam PS, Borrel G, Brochier-Armanet C, Gribaldo S (2017) The growing tree of Archaea: new perspectives on their diversity, evolution and ecology. ISME J 11(11): 2407-2425. PMID 28777382
- Borrel G, Brugère J-F, Gribaldo S, Schmitz RA, Moissl-Eichinger C (2020) The host-associated archaeome. Nat Rev Microbio 18(11):622-636. PMID 32690877
- Pende N, Sogues A, Megrian D, Sartori-Rupp A, England P, Palabikyan H, Rittmann SKR, Graña M, Wehenkel AM, Alzari PM, Gribaldo S (2021) SepF is the FtsZ anchor in archaea, with features of an ancestral cell division system. Nat Commun 4;12(1):3214. PMID 34088904
- Ithurbide S, Gribaldo S, Albers S, Pende N (2022) Spotlight on FtsZ-based cell division in Archaea. Trends Microbiol S0966-842X(22)00005-1. PMID: 35246355