@article{BenaventeReimerRoseetal.1988,
  author    = {Benavente, Ricardo and Reimer, Georg and Rose, Kathleen M. and H{\"u}gle-D{\"o}rr, Barbara and Scheer, Ulrich},
  title     = {Nucleolar changes after microinjection of antibodies to RNA polymerase I into the nucleus of mammalian cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40666},
  year      = {1988},
  abstract  = {After microinjection of antibodies against RNA polymerase I into the nuclei of cultured rat kangaroo (PtKz) and rat (RVF-SMC) cells alterations in nucleolar structure and composition were observed. These were detected by electron microscopy and double-label immunofluorescence microscopy using antibodies to proteins representative of the three major components of the nucleolus. The microinjected antibodies produced a progressive loss of the material of the dense fibrillar component (DFC) from the nucleoli which, at 4 h after injection, were transformed into bodies with purely granular component (GC) structure with attached fibrillar centers (FCs). Concomitantly, numerous extranucleolar aggregates appeared in the nucleoplasm which morphologically resembled fragments of the DFC and contained a protein (fibrillarin) diagnostic for this nucleolar structure. These observations indicate that the topological distribution of the material constituting the DFC can be experimentally influenced in interphase cells, apparently by modulating the transcriptional activity of the rRNA genes. These effects are different from nucleolar lesions induced by inhibitory drugs such as actinomycin D-dependent "nucleolar segregation". The structural alterations induced by antibodies to RNA polymerase I resemble, however, the initial events of nucleolar disintegration during mitotic prophase.},
  language  = {en}
}
@article{BenaventeRoseReimeretal.1987,
  author    = {Benavente, Ricardo and Rose, Kathleen M. and Reimer, Georg and H{\"u}gle-D{\"o}rr, Barbara and Scheer, Ulrich},
  title     = {Inhibition of nucleolar reformation after microinjection of antibodies to RNA polymerase I into mitotic cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33247},
  year      = {1987},
  abstract  = {The formation of daughter nuclei and the reformation of nucleolar structures was studied after microinjection of antibodies to RNA polymerase I into dividing cultured cells (PtK2). The fate of several nucleolar proteins representing the three main structural subcomponents of the nucleolus was examined by immunofluorescence and electron microscopy. The results show that the RNA polymerase I antibodies do not interfere with normal mitotic progression or the early steps of nucleologenesis, i.e. , the aggregation of nucleolar material into prenucleolar bodies. However,they inhibit the telophasic coalescence of the prenucleolar bodies into the chromosomal nucleolar organizer regions, thus preventing the formation of new nucleoli. These prenucleolar bodies show a fibrillar organization that also compositionally resembles the dense fibrillar component of interphase nucleoli . We conclude that during normal nucleologenesis the dense fibrillar component forms from preformed entities around nucleolar organizer regions, and that this association seems to be dependent on the presence of an active form of RNA polymerase I.},
  language  = {en}
}
@article{ReimerRaskaScheeretal.1988,
  author    = {Reimer, Georg and Raska, Ivan and Scheer, Ulrich and Tan, Eng M.},
  title     = {Immunolocalization of 7-2-ribonucleoprotein in the granular component of the nucleolus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33890},
  year      = {1988},
  abstract  = {Certain autoimmune sera contain antibodies against a nucleolar ribonucleoprotein particle associated with 7-2-RNA (R. Reddy et al. (1983) J. Bioi. Chem . 258, 1383; C. Hashimoto and J. A. Steitz (1983) J. Bioi. Chem. 258, 1379). In this study, we showed by immunofluorescence microscopy that antibodies reactive with 7-2-ribonucleoprotein immunolocalized in the granular regions of actinomycin D and 5,6-dichloro-I-j3-D-ribofuranosylbenzimidazole (DRB)-segregated nucleoli from Vero cells. By electron microscopic immunocytochemistry, antigen-antibody complexes were located in the granular component of transcriptionally active nucleoli from rat liver hepatocytes and HeLa cells. Anti-7- 2-RNP antibodies from two autoimmune sera immunoprecipitated a major protein of Mr 40,000 from e5S] methionine-Iabeled HeLa cell extract. The immunolocalization data suggest that 7-2-ribonucleoprotein may be involved in stages of ribosome biogenesis which take place in the granular component of the nucleolus, i.e., assembly, maturation, and/or transport of preribosomes},
  language  = {en}
}
@article{ReimerScheerPetersetal.1986,
  author    = {Reimer, Georg and Scheer, Ulrich and Peters, Jan-Michael and Tan, Eng M.},
  title     = {Immunolocalization and partial characterization of a nucleolar autoantigen (PM-Scl) associated with polymyositis / scleroderma overlap syndromes.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33191},
  year      = {1986},
  abstract  = {Precipitating anti-PM-Sel antibodies are present in sera from patients with polymyositis. scleroderma. and polymyositis/scleroderma overlap syndromes. By indirect immunofluorescence microscopy. anti-PM-Scl antibodies stained the nucleolus in cells of different tissues and species. suggesting that the antigen is highly conserved. By electron microscopy, anti-PM-Scl antibodies reacted primarily with the granular component of the nuc1eolus. Drugs that inhibit rRNA synthesis had a marked effect on the expression of PM-Scl antigen. In actinomycin D-treated cells, immunofluorescence staining by anti-PM-Scl was sign{\"u}icantly reduced with residual staining restricted to the granular regions of nuc1eoli. Treatment with 5,6-dichloro-beta-D- ribofuranosylbenzimidazole (DRB) also selectively reduced nuc1eolar staining. On a molecular level, anti-PM-Sel antibodies precipitated 11 polypeptides with molecular weights (Mr) ranging from 110,000 to 20,000. The Mr 80,000 and 20.000 polypeptides were phosphorylated. Evidence suggests that the PM-Scl antigen complex may be related to a prerlbosomal particle.},
  language  = {en}
}
@misc{ReimerRaskaTanetal.1987,
  author    = {Reimer, Georg and Raska, Ivan and Tan, Eng M. and Scheer, Ulrich},
  title     = {Human autoantibodies: probes for nucleolus structure and function},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-41410},
  year      = {1987},
  abstract  = {No abstract available},
  language  = {en}
}
@article{ReimerRoseScheeretal.1987,
  author    = {Reimer, Georg and Rose, Kathleen M. and Scheer, Ulrich and Tan, Eng M.},
  title     = {Autoantibody to RNA polymerase I in scleroderma sera},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34294},
  year      = {1987},
  abstract  = {Autoantibodies to components of the nucleolus are a unique serological feature of patients with scleroderma. There are autoantibodies of several specificities; one type produces a speckled pattern of nucleolar staining in immunofluorescence. In actinomycin D and 5,6-dichloro-{j-D-ribofuranosylbenzimidazoletreated Vero cells, staining was restricted to the fibrillar and not the granular regions. By double immunofluorescence, specific rabbit anti-RNA polymerase I antibodies stained the same fibrillar structures in drug-segregated nucleoli as scleroderma sera. Scleroderma sera immunoprecipitated 13 polypeptides from (35S)methionine-labeled HeLa cell extract with molecular weights ranging from 210,000 to 14,000. Similar polypeptides were precipitated by rabbit anti-RNA polymerase I antibodies, and their common identities were confirmed in immunoabsorption experiments. Microinjection of purified IgG from a patient with speckled nucleolar staining effectively inhibited ribosomal RNA transcription. Autoantibodies to RNA polymerase I were restricted to certain patients with scleroderma and were not found in other autoimmune diseases.},
  language  = {en}
}