The $in\ vivo$ mechanics of the magnetotactic backbone as revealed by correlative FLIM-FRET and STED microscopy

Erika Günther (1) , André Klauss (2) , Mauricio Toro-Nahuelpan (3, 4) , Dirk Schüler (3) , Carsten Hille (5) , Damien Faivre (1, 6)

1 Department of Biomaterials [Potsdam]
2 University of Potsdam = Universität Potsdam
3 University of Bayreuth
4 EMBL - European Molecular Biology Laboratory [Heidelberg]
5 Institut für Chemie [Universität Potsdam] | Institute of Chemistry [University of Potsdam]
6 BIAM - Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB)

Protein interaction and protein imaging strongly benefit from the advancements in time-resolved and superresolution fluorescence microscopic techniques. However, the techniques were typically applied separately and ex vivo because of technical challenges and the absence of suitable fluorescent protein pairs. Here, we show correlative in vivo fluorescence lifetime imaging microscopy Förster resonance energy transfer (fLiM-fRet) and stimulated emission depletion (SteD) microscopy to unravel protein mechanics and structure in living cells. We use magnetotactic bacteria as a model system where two proteins, MamJ and MamK, are used to assemble magnetic particles called magnetosomes. The filament polymerizes out of MamK and the magnetosomes are connected via the linker MamJ. Our system reveals that bacterial filamentous structures are more fragile than the connection of biomineralized particles to this filament. More importantly, we anticipate the technique to find wide applicability for the study and quantification of biological processes in living cells and at high resolution.

Domaines: Sciences du Vivant [q-bio]

Erika Günther, André Klauss, Mauricio Toro-Nahuelpan, Dirk Schüler, Carsten Hille, et al.. The $in\ vivo$ mechanics of the magnetotactic backbone as revealed by correlative FLIM-FRET and STED microscopy. Scientific Reports, 2019, 9, pp.19615. ⟨10.1038/s41598-019-55804-5⟩. ⟨cea-02440823⟩