title: The composition and morphology of yeast nuclear scaffolds.
abstract: The yeast nuclear scaffold has been shown to bind with high affinity to genomic sequences that permit autonomous DNA replication of plasmids (ARS elements). We describe here conditions for the isolation of a histone-free nuclear substructure, the nuclear scaffold, from Saccharomyces cerevisiae. We examine the protein composition of this structure,and the conditions under which topoisomerase II, the nuclear factor RAP-1 and RNA polymerase II co-fractionate with the scaffold. We find that exposure of nuclei to a combined metal and heat treatment (0.5mM Cu(2) +, 37 degree centigrade prior to detergent extraction is required for effective stabilization of these proteins with the scaffold. Electron microscopy of the residual nuclei extracted with non-ionic detergents shows the absence of a typical peripheral lamina structure.
authors.affiliation: Swiss Institute for Experimental Cancer Research (ISREC), Chemin des Boveresses 155, CH-1066 Epalinges/Lausanne, Switzerland.
authors.forename: M E
authors.initials: ME
authors.lastname: Cardenas
authors.forename: T
authors.initials: T
authors.lastname: Laroche
authors.forename: S M
authors.initials: SM
authors.lastname: Gasser
mesh_terms: D002458:Cell Fractionation; D002467:Cell Nucleus / Q000648:ultrastructure; D004250:DNA Topoisomerases, Type II / Q000032:analysis; D012321:DNA-Directed RNA Polymerases / Q000032:analysis; D006358:Hot Temperature; D008670:Metals / Q000494:pharmacology; D015530:Nuclear Matrix / Q000737:chemistry* / Q000648:ultrastructure*; D034521:Nuclear Matrix-Associated Proteins / Q000032:analysis*; D009687:Nuclear Proteins / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000254:growth & development / Q000648:ultrastructure*; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis*
chemical_list: D008670:Metals; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D012321:DNA-Directed RNA Polymerases; D004250:DNA Topoisomerases, Type II