Proteins Bound to Heterogeneous Nuclear RNA of Siman-Virus-40-Infected Cells

Abstract

Heterogeneous nuclear RNA.cntdot.protein (hnRNA.cntdot.protein) complexes from SV-40-infected [African green monkey kidney CU-1] cells late in infection contain 7-10% RNA sequences specific to SV-40 DNA. The SV-40 nuclear RNA.cntdot.protein complexes sediment at 60-70 S. The reality and specificity of the RNA-protein association is shown in metrizamide gradients. Protein and RNA labels of hnRNA.cntdot.protein-particles in SV-40-infected cells follow a parallel pattern with a peak at 1.28 g/cm2 but a mixture of rRNA and soluble cytoplasmic proteins is separated according to the different densities in metrizamide. Analysis of hnRNA.cntdot.protein from infected cells by 2-dimensional gel electrophoresis shows the presence of a number of new proteins. Three of these proteins are cellular ones induced by the virus infection and hence constitute good candidates to be specific RNA.cntdot.protein particles for virus nuclear RNA. The presence of actin in hnRNA.cntdot.protein .pi. particles from normal and SV-40-infected cells and the presence of the major capsid protein VP1 in hnRNA.cntdot.protein particles from SV-40-infected cells is discussed.