title: Pigpen is a cellular binding protein of therapeutic oligonucleotides.
abstract: BACKGROUND
  Understanding the mechanism of oligonucleotide (ON) uptake and cellular distribution is important for rational design of ON-based therapeutic strategies. The aim of this study was to investigate the possible relationship between cellular distribution of ON and the protein pigpen.
  
  
  METHODS
  In vitro interaction of ON with the protein pigpen was detected using mass spectrometry. Cellular distribution of pigpen and co-localization of pigpen with ON was studied by fluorescence microscopy in endothelial YPEN and microglial N9 cells.
  
  
  RESULTS
  Pigpen had similar distribution patterns in endothelial YPEN and microglial N9 cells. Pigpen was localized to the cytoplasm of both cell types. In addition, pigpen distributed to nuclei, excluding the nucleoli, and concentrated along the nuclear membrane and plasma membrane. Intensely stained foci were only observed in the nucleus and cytoplasm of YPEN cells. Although co-localization of pigpen with phosphorothioate (PS) ON was not observed for the first hour after ON uptake, co-localization was observed 8 h later.
  
  
  CONCLUSIONS
  These data suggest that pigpen binds therapeutic ON and thus might contribute to ON cellular distribution.
authors.affiliation: Institute of Brain Research, University of Tuebingen, Calwer Strasse 3, D-72076 Tuebingen, Germany.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: H J
authors.initials: HJ
authors.lastname: Schluesener
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000502:physiology; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism*; D051379:Mice; D009841:Oligonucleotides / Q000378:metabolism / Q000494:pharmacology*; D011485:Protein Binding / Q000502:physiology; D016601:RNA-Binding Proteins / Q000378:metabolism*; D051381:Rats; D034702:RNA-Binding Protein FUS
chemical_list: D004268:DNA-Binding Proteins; D009841:Oligonucleotides; D016601:RNA-Binding Proteins; C000599551:FUS protein, mouse; D034702:RNA-Binding Protein FUS