title: Demonstration of a dynamic, transcription-dependent organization of pre-mRNA splicing factors in polytene nuclei.
abstract: We describe the dynamic organization of pre-mRNA splicing factors in the intact polytene nuclei of the dipteran Chironomus tentans. The snRNPs and an SR non-snRNP splicing factor are present in excess, mainly distributed throughout the interchromatin. Approximately 10% of the U2 snRNP and an SR non-snRNP splicing factor are associated with the chromosomes, highly enriched in active gene loci where they are bound to RNA. We demonstrate that the splicing factors are specifically recruited to a defined gene upon induction of transcription during physiological conditions. Concomitantly, the splicing factors leave gene loci in which transcription is turned off. We also demonstrated that upon general transcription inhibition, the splicing factors redistribute from active gene loci to the interchromatin. Our findings demonstrate the dynamic intranuclear organization of splicing factors and a tight linkage between transcription and the intranuclear organization of the splicing machinery.
authors.affiliation: Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institutet, Stockholm, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Baurén
authors.forename: W Q
authors.initials: WQ
authors.lastname: Jiang
authors.forename: K
authors.initials: K
authors.lastname: Bernholm
authors.forename: F
authors.initials: F
authors.lastname: Gu
authors.forename: L
authors.initials: L
authors.lastname: Wieslander
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002683:Chironomidae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D002843:Chromatin / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D005690:Galactose / Q000494:pharmacology; D005786:Gene Expression Regulation; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing / Q000187:drug effects; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000378:metabolism; D012469:Salivary Glands / Q000378:metabolism / Q000648:ultrastructure; D017381:Spliceosomes / Q000187:drug effects / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D002843:Chromatin; D011500:Protein Synthesis Inhibitors; D012322:RNA Precursors; D017413:Ribonucleoprotein, U2 Small Nuclear; D003609:Dactinomycin; D004004:Dichlororibofuranosylbenzimidazole; D005690:Galactose