RNP Particles, Splicing and Autoimmune Diseases, 1998 Springer Lab Manuals Series

The first insights into the site and mechanisms of RNA process­ ing to functional mRNA in eukaryotic cells came from the group of Georgiev (Lukanidin et al. 1972) who demonstrated the association of rapidly labelled, heterogeneous nuclear RNA (hnRNA) with a limited number of specific proteins in the cell nucleus. These "informofers", i. e. packaged precursors of mRNA (pre-mRNA or hnRNA), are in a form presumably amenable to the action of nucleases. With the availability of better analytical techniques, the considerable heterogeneity of hnRNA associated proteins was revealed (Niessing and Sekeris 1970), suggesting a role that was more composite, rather than solely structural, for these proteins. Later studies investigated the RNA binding behavior of these proteins (Schenkel et al. 1988, 1989, Wilk et al. 1983). For a long time, the small nuclear RNAs, well characterized with respect to primary structure (reviewed by Reddy and Busch 1983), were naively ignored regarding their function. Several events then set the stage for a detailed study of the intricate mechanisms of the splicing process and other steps involved in hnRNA processing: (1) The demonstration of a second class of nuclear ribonucleoproteins (RNPs), composed of small nuclear RNAs (snRNAs) and another characteristic group ofheterogene­ ous proteins (Lerner et al. 1980, Guialis et al. 1983), (2) the detec­ tion of the association of snRNPs with hnRNPs by virtue of base pairing between hnRNA and snRNA (Flytzanis et al.

Frank Jung, Constantin E. Sekeris, and Johannes Schenkel: Isolation and Immunochemical Characterization of hnRNP Particles.-Ruth Sperling and Joseph Sperling: The lnRNP Particle -- A Naturally Assembled Complex of Pre-mRNA and Splicing Factors.-Karl Otto Greulich: Intrinsic Fluorescence Techniques for Studies on Protein-Protein and Protein-RNA Interactions in RNP Particles.-Ulf Skoglund, Lars-Göran Öfverstedt, and Bertil Daneholt: Procedures for Three-Dimensional Reconstruction from Thin Sections with Electron Tomography.-Berthold Kastner: Purification and Electron Microscopy of Spliceosomal snRNPs.-Panayiotis G. Vlachoyiannopoulos: Detection of Autoantibodies to Extractable Cellular Antigens.-Martin Blüthner: Methods in Immunolocalization of Autoantigens.- Johannes Schenkel, Frank Jung, Apostolia Guialis, and Angela Krämer: In Vitro Splicing of Pre-mRNA in HeLa Extracts.