title: Nuclear protein migration involves two steps: rapid binding at the nuclear envelope followed by slower translocation through nuclear pores.
abstract: When injected into the cytoplasm of Vero cells, nucleoplasmin rapidly concentrates in a narrow layer around the nuclear envelope and then accumulates within the nucleus. Transport into the nucleus can be reversibly arrested at the perinuclear stage by metabolic inhibitors or by chilling. Nucleoplasmin-coated colloidal gold particles concentrate around the nuclear envelope of Vero cells or Xenopus oocytes, and by electron microscopy of oocytes appear to be associated with fibrils attached to nuclear pore complexes. Perinuclear accumulation is not observed for the nonmigrating nucleoplasmin core fragment or nonnuclear proteins. We propose two steps in nuclear migration of proteins: rapid binding around the nuclear envelope, possibly to pore-associated fibrils, followed by slower, energy-dependent translocation through nuclear pores.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001386:Azides / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002467:Cell Nucleus / Q000378:metabolism*; D003080:Cold Temperature; D003593:Cytoplasm / Q000378:metabolism; D003847:Deoxyglucose / Q000494:pharmacology; D005260:Female; D005455:Fluorescent Antibody Technique; D006046:Gold; D006651:Histocytochemistry; D008854:Microscopy, Electron; D009685:Nuclear Envelope / Q000378:metabolism* / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000378:metabolism*; D056489:Nucleoplasmins; D009865:Oocytes / Q000648:ultrastructure; D010434:Pepsin A / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D010750:Phosphoproteins; D019810:Sodium Azide; D014709:Vero Cells; D014982:Xenopus laevis
chemical_list: D001386:Azides; D009687:Nuclear Proteins; D056489:Nucleoplasmins; D010446:Peptide Fragments; D010750:Phosphoproteins; D006046:Gold; D000255:Adenosine Triphosphate; D019810:Sodium Azide; D003847:Deoxyglucose; D010434:Pepsin A