Biosciences and Biotechnology Institute of Aix-Marseille
Research Topic, MEM
Chercheurs: Damien FAIVRE, Christopher LEFEVRE, Pascal ARNOUX & David PIGNOLTechniciens/Ingénieurs: Géraldine ADRYANCZYK, Béatrice ALONSO & Sandra PREVERALDoc: Anissa DIEUDONNE, François MATHONPostDoc: Caroline MONTEIL
Emiritus researcher: Michel PEAN
Magnetotactic bacteria (MTB) represent a very
diverse group of prokaryotes that do not form a separate branch in the tree of
life but are rather spread in three different phyla: Proteobacteria, Nitrospirae
and Omnitrophica. MTB diversity is still
under-evaluated and our group contributed in the last period to the isolation
and description of several new MTB strains from environmental samplings. Using comparative genomic
analysis applied to various cultured or uncultured species, we were able (i) to
decipher essential genes for magnetosome formation based on their conservation
in the different groups of MTB, ii) to evidence
genes specifically involved in controlling the shape of the biomineralized iron-rich
particles, iii) to propose hypothesis on the historical evolution of
magnetosomes, (iv) to describe original
bacterial functions in MTB related to aero- magneto- taxis and cellular division. In this topic, a pioneering result obtained in the
last years was the isolation in pure culture of the first magnetite (iron
oxide) and greigite (iron sulfur) producer (BW-1), a discovery published in Science in 2011. The genome of
this strain is now completely sequenced which paves the way to the
full characterization of the genetic and environmental determinants controlling
the chemical composition of the biomineralized crystal.
A large genomic island, conserved among magnetotactic bacteria, contains genes potentially involved in magnetosome formation, most of them encoding proteins of unknown function. We deciphered in the last period original protein functions required for magnetosome alignment and magnetite biomineralization. We are interested in the function of MamK, an "actin-like" responsible for the alignment of the magnetosomes chain (5,13). Transcriptional regulator controlling the synthesis of the organelle has also been characterized (12). Electron transfer mechanisms required for the biomineralization of magnetite nanocrystals are also addressed by the study of specific redox proteins. Thus, we were able to identify 4 Mam proteins (MAMP, T, X and E) that contain a new type of single-heme cytochrome specific to MTBs and coined the magnetochrome (6, 10). We have characterized MamP in details: it is an iron oxidase whose activity is required to control the redox balance of iron. The structure of MamP also highlights the unique folding of the magnetochrome domain that represents the smaller mono-heme cytochrome described to date (9).
MamP is anironoxidase whose activity is required to control the redox balanceof iron.
ANR Tremplin-ERC BIOMAGNET; 2017-2018, coordinator C. Lefevre
Ministry of Business, Innovation and Employment (MBIE) Nouvelle Zélande, 2018- 2019, collaborator C. Lefevre (coordinator R. Weld)
Defi ISOTOP-CNRS, 2018, coordinator C. lefevre
ANR SIGMAG, 2018-2021, coordinators V. Busigny and D. Pignol
Plan Sangnier A, Preveral S, Curcio A, K A Silva A, Lefèvre CT, Pignol D, Lalatonne Y, Wilhelm C (2018) Targeted thermal therapy with genetically engineered magnetite magnetosomes@RGD: Photothermia is far more efficient than magnetic hyperthermia. J Control Release. 279:271-281. doi: 10.1016/j.jconrel.2018.04.036
Smit BA, Van Zyl E, Joubert JJ, Meyer W, Prévéral S, Lefèvre CT, Venter SN (2018) Magnetotactic bacteria used to generate electricity based on Faraday's law of electromagnetic induction. Let Appl Microbiol. 66:362-367. doi: 10.1111/lam.12862
Boucher M, Geffroy F, Prévéral S, Bellanger L, Selingue E, Adryanczyk-Perrier G, Péan M, Lefèvre CT, Pignol D, Ginet N, Mériaux S. (2017) Genetically tailored magnetosomes used as MRI probe for molecular imaging of brain tumor. Biomaterials. 121:167-178 doi: 10.1016/j.biomaterials.2016.12.013.
Lefèvre CT, Menguy N, Abreu F, Lins U, Pósfai M, Prozorov T, Pignol D, Frankel RB, Bazylinski DA (2011) A Cultured Greigite-Producing Magnetotactic Bacterium in a Novel Group of Sulfate-Reducing Bacteria. Science 334(6063):1720-3.
Lefèvre CT, Trubitsyn D, Abreu F, Kolinko S, Gonzaga Paula de Almeida L, R de Vasconcelos AT, Kube M, Reinhardt R, Schüler D, Lins U, Pignol D, Bazylinski D, Ginet N (2013) "Comparative Genomics Analysis of Magnetotactic Bacteria of the Deltaproteobacteria Give a New Insight into the Magnetite and Greigite Magnetosome Genes Required for Magnetotaxis" Env Microb doi: 10.1111/1462-2920.12128
Rivas-Lamelo S, Benzerara K, Lefèvre CT, Monteil CL, Jézéquel D, Menguy N, Viollier E, Guyot F, Férard C, Poinsot M, Skouri-Panet F, Trcera N, Miot J, Duprat E (2017) Magnetotactic bacteria as a new model for P sequestration in the ferruginous Lake Pavin. Geochem Persp Let. 5:35-41.
Monteil CL, Menguy N, Prévéral S, Warren A, Pignol D, Lefèvre CT (2018) Accumulation and dissolution of magnetite crystals in a magnetically responsive ciliate. Appl Environ Microbiol. e02865-17. doi: 10.1128/AEM.02865-17
Siponen M, Adryanczyk G, Ginet N, Arnoux P, Pignol D (2012) An Electron Transfer chain for Magnetotatic Bacteria Organelle Formation.Biochem Soc Trans 1;40(6):1319-23.
Abreu N, Mannoubi S, Ozyamak E, Pignol D, Ginet N, Komeili A. (2014) The interplay between two bacterial actin homologs, MamK and MamK-like, is required for the alignment of magnetosome organelles in Magnetospirillum magneticum AMB-1 J. Bacteriol Sep 1;196(17):3111-21. doi: 10.1128/JB.01674-14. Epub 2014
LiY, Sabaty M, Borg S, Silva KT, Pignol D, Schüler D. (2014) The oxygen sensor MgFnr controls magnetite biomineralization by regulation of denitrification in Magnetospirillum gryphiswaldense. BMC Microbiology Jun 10;14:153. doi: 10.1186/1471-2180-14-153
Lefèvre C.T., Bennet M., Klumpp S. & Faivre D. (2015) « Positioning the flagellum at the center to combine bacterial division with magnetic polarity » mBio Feb 24;6(2). pii: e02286-14. doi: 10.1128/mBio.02286
Lefèvre CT, Bennet M, Landau L, Vach P, Pignol D, Bazylinski D, Frankel R, Klumpp S, Faivre D. (2014) Diversity of magneto-aerotactic behaviours and oxygen sensing mechanisms in cultured magnetotactic bacteria . Biophysical Journal 15;107(2):527-38. doi: 10.1016/j.bpj.2014.05.043
Klumpp S, Lefèvre CT, Bennet M, Faivre D (2019) Swimming with magnets: From biological organisms to synthetic devices. Physics Reports 789:1–54 doi.org/10.1016/j.physrep.2018.10.007
Lefèvre CT, Bazylinski DA (2013) Ecology, diversity, and evolution of magnetotactic bacteria. Microbiol Mol Biol. 77:497-526. doi: 10.1128/MMBR.00021-13
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