Splicing of messenger RNA precursors is inhibited by antisera to small nuclear ribonucleoprotein

Abstract

A mouse monoclonal antibody and human autoimmune sera directed against various classes of small ribonucleoprotein particles have been tested for inhibition of mRNA splicing in a soluble in vitro system. The splicing of the first and second leader exons of adenovirus late RNA was inhibited only by those sera that reacted with U1 RNP. Both U1 RNP-specific human autoimmune serum and sera directed against the Sm class of small nuclear RNPs, including a mouse monoclonal antibody, specifically inhibited splicing. Antisera specific for U2 RNP had no effect on splicing nor did antisera specific for the La or Ro class of small RNPs. These results suggest that U1 RNP is essential for the splicing of mRNA precursors.