@article{DunsingLucknerZuehlkeetal.2018,
  author    = {Dunsing, Valentin and Luckner, Madlen and Zuehlke, Boris and Petazzi, Roberto Arturo and Herrmann, Andreas and Chiantia, Salvatore},
  title     = {Optimal fluorescent protein tags for quantifying protein oligomerization in living cells},
  series = {Scientific reports},
  volume    = {8},
  journal   = {Scientific reports},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-018-28858-0},
  pages     = {12},
  year      = {2018},
  abstract  = {Fluorescence fluctuation spectroscopy has become a popular toolbox for non-disruptive analysis of molecular interactions in living cells. The quantification of protein oligomerization in the native cellular environment is highly relevant for a detailed understanding of complex biological processes. An important parameter in this context is the molecular brightness, which serves as a direct measure of oligomerization and can be easily extracted from temporal or spatial fluorescence fluctuations. However, fluorescent proteins (FPs) typically used in such studies suffer from complex photophysical transitions and limited maturation, inducing non-fluorescent states. Here, we show how these processes strongly affect molecular brightness measurements. We perform a systematic characterization of non-fluorescent states for commonly used FPs and provide a simple guideline for accurate, unbiased oligomerization measurements in living cells. Further, we focus on novel red FPs and demonstrate that mCherry2, an mCherry variant, possesses superior properties with regards to precise quantification of oligomerization.},
  language  = {en}
}
@misc{LucknerDunsingChiantiaetal.2018,
  author    = {Luckner, Madlen and Dunsing, Valentin and Chiantia, Salvatore and Hermann, Andreas},
  title     = {Oligomerization and nuclear shuttling dynamics of viral proteins studied by quantitative molecular brightness analysis using fluorescence correlation spectroscopy},
  series = {Biophysical journal},
  volume    = {114},
  journal   = {Biophysical journal},
  number    = {3},
  publisher = {Cell Press},
  address   = {Cambridge},
  issn      = {0006-3495},
  doi       = {10.1016/j.bpj.2017.11.1951},
  pages     = {350A -- 350A},
  year      = {2018},
  language  = {en}
}
@misc{DunsingMagnusLiebschetal.2018,
  author    = {Dunsing, Valentin and Magnus, Mayer and Liebsch, Filip and Multhaup, Gerhard and Chiantia, Salvatore},
  title     = {Direct Evidence of APLP1 Trans Interactions in Cell-Cell Adhesion Platforms Investigated via Fluorescence Fluctuation Spectroscopy},
  series = {Biophysical journal},
  volume    = {114},
  journal   = {Biophysical journal},
  number    = {3},
  publisher = {Cell Press},
  address   = {Cambridge},
  issn      = {0006-3495},
  doi       = {10.1016/j.bpj.2017.11.2067},
  pages     = {373A -- 373A},
  year      = {2018},
  abstract  = {The Amyloid-precursor-like protein 1 (APLP1) is a neuronal type I transmembrane protein which plays a role in synaptic adhesion and synaptogenesis. Past investigations indicated that APLP1 is involved in the formation of protein-protein complexes that bridge the junctions between neighboring cells. Nevertheless, APLP1-APLP1 trans interactions have never been directly observed in higher eukaryotic cells. Here, we investigate APLP1 interactions and dynamics directly in living human embryonic kidney (HEK) cells, using fluorescence fluctuation spectroscopy techniques, namely cross-correlation scanning fluorescence correlation spectroscopy (sFCS) and Number\&Brightness (N\&B). Our results show that APLP1 forms homotypic trans complexes at cell-cell contacts. In the presence of zinc ions, the protein forms macroscopic clusters, exhibiting an even higher degree of trans binding and strongly reduced dynamics. Further evidence from Giant Plasma Membrane Vesicles and live cell actin staining suggests that the presence of an intact cortical cytoskeleton is required for zinc-induced cis multimerization. Subsequently, large adhesion platforms bridging interacting cells are formed through APLP1-APLP1 direct trans interactions. Taken together, our results provide direct evidence that APLP1 functions as a neuronal zinc-dependent adhesion protein and provide a more detailed understanding of the molecular mechanisms driving the formation of APLP1 adhesion platforms. Further, they show that fluorescence fluctuation spectroscopy techniques are useful tools for the investigation of protein-protein interactions at cell-cell adhesion sites.},
  language  = {en}
}