Evidence that a nuclear matrix protein participates in premessenger RNA splicing

Exp Cell Res. 1989 Jun;182(2):521-33. doi: 10.1016/0014-4827(89)90255-3.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antibodies
  • Antigens, Nuclear
  • Autoantigens / genetics*
  • Cell Nucleus / metabolism*
  • Cross Reactions
  • HeLa Cells / metabolism
  • Humans
  • Immunoblotting
  • Molecular Weight
  • Nuclear Proteins / analysis
  • Nuclear Proteins / genetics*
  • RNA Precursors / genetics*
  • RNA Splicing*

Substances

  • Antibodies
  • Antigens, Nuclear
  • Autoantigens
  • Nuclear Proteins
  • RNA Precursors