title: Interaction of proteins associated with the magnetosome assembly in magnetotactic bacteria as revealed by two-hybrid two-photon excitation fluorescence lifetime imaging microscopy Förster resonance energy transfer.
abstract: Bacteria have recently revealed an unexpectedly complex level of intracellular organization. Magnetotactic bacteria represent a unique class of such organization through the presence of their magnetosome organelles, which are organized along the magnetosome filament. Although the role of individual magnetosomes-associated proteins has started to be unraveled, their interaction has not been addressed with current state-of-the-art optical microscopy techniques, effectively leaving models of the magnetotactic bacteria protein assembly arguable. Here we report on the use of FLIM-FRET to assess the interaction of MamK (actin-like protein) and MamJ, two magnetosome membrane associated proteins essential to the assembly of magnetosomes in a chain. We used a host organism (E. coli) to express eGFP_MamJ and MamK_mCherry, the latest expectedly forming a filament. We found that in the presence of MamK the fluorescence of eGFP_MamJ is distributed along the MamK filament. FRET analysis using the fluorescence lifetime of the donor, eGFP, revealed a spatial proximity of MamK_mCherry and eGFP_MamJ typical of a stable physical interaction between two proteins. Our study effectively led to the reconstruction of part of the magnetotactic apparatus in vivo.
authors.affiliation: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces , Science Park Golm, 14424 Potsdam, Germany.
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Carillo
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bennet
authors.forename: Damien
authors.initials: D
authors.lastname: Faivre
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D055944:Magnetosomes / Q000378:metabolism*; D042201:Magnetospirillum / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D025941:Protein Interaction Mapping; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D000097573:Red Fluorescent Protein
chemical_list: D001426:Bacterial Proteins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D000097573:Red Fluorescent Protein