Immunopurification of heterogeneous nuclear ribonucleoprotein particles reveals an assortment of RNA-binding proteins.

• DOI: 10.1101/gad.2.2.215
• Publication Date: 2007-06-05T21:15:46Z
• Authors: S Piñol-Roma; Y D Choi; M J Matunis; G Dreyfuss
• Keywords: Heterogeneous nuclear ribonucleoprotein; Heterogeneous ribonucleoprotein particle; Nuclear matrix; Non-histone protein

Heterogeneous nuclear RNA-ribonucleoprotein (hnRNP) particles can be efficiently purified by a specific, rapid, and mild procedure using monoclonal antibodies to hnRNP proteins. We report here on the detailed analysis of protein composition immunopurified from human HeLa cells. By two-dimensional gel electrophoresis, contain at least 24 polypeptides in range 34,000-120,000 daltons. The abundant 30,000-40,000 dalton proteins, A, B, C, described previously, are subset these polypeptides. compositions found nucleoplasm fraction chromatin-nucleolar very similar. Upon addition polyanion heparin, most major proteins remain associated heparin-resistant particles, only several, mostly minor, dissociate. This provides an aid classification additional criterion for definition particle components. Chromatography single-stranded DNA (ssDNA)-agarose heparin- moderate or high salt (higher than 300 mM NaCl)-resistant manner suggests that most, if not all, nucleic acid-binding describe general method large-scale purification affinity chromatography ssDNA columns its use production new