title: Actin polymerisation at the cytoplasmic face of eukaryotic nuclei.
abstract: BACKGROUND
  There exists abundant molecular and ultra-structural evidence to suggest that cytoplasmic actin can physically interact with the nuclear envelope (NE) membrane system. However, this interaction has yet to be characterised in living interphase cells.
  
  
  RESULTS
  Using a fluorescent conjugate of the actin binding drug cytochalasin D (CD-BODIPY) we provide evidence that polymerising actin accumulates in vicinity to the NE. In addition, both transiently expressed fluorescent actin and cytoplasmic micro-injection of fluorescent actin resulted in accumulation of actin at the NE-membrane. Consistent with the idea that the cytoplasmic phase of NE-membranes can support this novel pool of perinuclear actin polymerisation we show that isolated, intact, differentiated primary hepatocyte nuclei support actin polymerisation in vitro. Further this phenomenon was inhibited by treatments hindering steric access to outer-nuclear-membrane proteins (e.g. wheat germ agglutinin, anti-nesprin and anti-nucleoporin antibodies).
  
  
  CONCLUSIONS
  We conclude that actin polymerisation occurs around interphase nuclei of living cells at the cytoplasmic phase of NE-membranes.
authors.affiliation: Unité de Biologie Cellulaire du Noyau, CNRS URA 2582, Département de Biologie Cellulaire et Infection, Institut Pasteur, 25, Rue du Docteur Roux, 75724 Paris Cedex 15, France. sylvia.muenter@med.uni-heidelberg.de
authors.forename: Sylvia
authors.initials: S
authors.lastname: Münter
authors.forename: Jost
authors.initials: J
authors.lastname: Enninga
authors.forename: Rafael
authors.initials: R
authors.lastname: Vazquez-Martinez
authors.forename: Erwan
authors.initials: E
authors.lastname: Delbarre
authors.forename: Brigitte
authors.initials: B
authors.lastname: David-Watine
authors.forename: Ulf
authors.initials: U
authors.lastname: Nehrbass
authors.forename: Spencer L
authors.initials: SL
authors.lastname: Shorte
mesh_terms: D000199:Actins / Q000737:chemistry*; D000818:Animals; D001665:Binding Sites; D001704:Biopolymers; D001896:Boron Compounds / Q000032:analysis; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002942:Circular Dichroism; D015638:Cytochalasin D / Q000494:pharmacology; D047630:Depsipeptides / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000032:analysis; D006367:HeLa Cells; D006801:Humans; D008099:Liver / Q000648:ultrastructure; D009685:Nuclear Envelope / Q000737:chemistry*; D011817:Rabbits; D051381:Rats; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D000199:Actins; D001704:Biopolymers; D001896:Boron Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D047630:Depsipeptides; D005456:Fluorescent Dyes; D013844:Thiazoles; D053778:Thiazolidines; C057531:jasplakinolide; D015638:Cytochalasin D; C037067:latrunculin A