title: Evidence that a nuclear matrix protein participates in premessenger RNA splicing.
abstract: The role of nuclear matrix proteins in premessenger RNA splicing has been investigated using antibodies raised against isolated rat liver nuclear matrix and cross-reactive with a 65-kDa HeLa cell nuclear matrix protein (IGA-65). IGA-65 is an internal nuclear matrix component which can be solubilized as a component of nuclear splicing extracts, by the action of endogenous ribonucleases, EDTA, and DTT during extract preparation. Preincubation of splicing extract with antibodies against IGA-65 (anti-IGA-65) inhibited in vitro splicing of exogenous adenovirus precursor RNA. Furthermore, assembly of precursor RNA into active spliceosome complexes was inhibited by pretreatment of extracts with anti-IGA-65, suggesting a role for IGA-65 during early spliceosome assembly. The IGA-65 present in splicing extracts was distinguishable from known U-snRNP and hnRNP proteins on protein gels. Furthermore, electrophoresis of splicing extract on native gels indicated that IGA-65 was present in protein complexes different from those containing U-snRNPs or hnRNP C protein. The data support identification of complexes containing IGA-65 as nuclear factors involved in pre-mRNA splicing and, by extension, suggest a role for the nuclear matrix during processing in vivo.
authors.affiliation: Department of Pathology, University of Rochester, New York 14642.
authors.forename: H C
authors.initials: HC
authors.lastname: Smith
authors.forename: S G
authors.initials: SG
authors.lastname: Harris
authors.forename: M
authors.initials: M
authors.lastname: Zillmann
authors.forename: S M
authors.initials: SM
authors.lastname: Berget
mesh_terms: D000906:Antibodies; D034961:Antigens, Nuclear; D001324:Autoantigens / Q000235:genetics*; D002467:Cell Nucleus / Q000378:metabolism*; D003429:Cross Reactions; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics*; D012322:RNA Precursors / Q000235:genetics*; D012326:RNA Splicing
chemical_list: D000906:Antibodies; D034961:Antigens, Nuclear; D001324:Autoantigens; D009687:Nuclear Proteins; D012322:RNA Precursors