title: Quantitative fluorescence imaging of protein diffusion and interaction in living cells.
abstract: Diffusion processes and local dynamic equilibria inside cells lead to nonuniform spatial distributions of molecules, which are essential for processes such as nuclear organization and signaling in cell division, differentiation and migration. To understand these mechanisms, spatially resolved quantitative measurements of protein abundance, mobilities and interactions are needed, but current methods have limited capabilities to study dynamic parameters. Here we describe a microscope based on light-sheet illumination that allows massively parallel fluorescence correlation spectroscopy (FCS) measurements and use it to visualize the diffusion and interactions of proteins in mammalian cells and in isolated fly tissue. Imaging the mobility of heterochromatin protein HP1α (ref. 4) in cell nuclei we could provide high-resolution diffusion maps that reveal euchromatin areas with heterochromatin-like HP1α-chromatin interactions. We expect that FCS imaging will become a useful method for the precise characterization of cellular reaction-diffusion processes.
authors.affiliation: Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Capoulade
authors.forename: Malte
authors.initials: M
authors.lastname: Wachsmuth
authors.forename: Lars
authors.initials: L
authors.lastname: Hufnagel
authors.forename: Michael
authors.initials: M
authors.lastname: Knop
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004058:Diffusion; D004285:Dogs; D004330:Drosophila / Q000166:cytology; D022041:Euchromatin / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D005822:Genetic Vectors / Q000235:genetics; D006570:Heterochromatin / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000166:cytology; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence / Q000379:methods*; D025941:Protein Interaction Mapping / Q000379:methods*; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: C000715594:CBX5 protein, human; D002868:Chromosomal Proteins, Non-Histone; D022041:Euchromatin; D006570:Heterochromatin; D011506:Proteins; D000090266:Chromobox Protein Homolog 5