Nuclear RNP-particles bearing rapidly-labeled heterogeneous RNA from pea embryos

Abstract

Ribonucleoprotein (RNP)-particles were extracted from the nuclei-enriched fraction of pea embryos which were pulse-labeled with 3H-uridine or 3H-adenosine. These nuclear RNP-particles sedimented heterodispersedly through a KCl-Mg-containing sucrose gradient with rather discrete peaks of 67–71, 53–55, 41–44, 33–35 and 20–22S. These complexes were obtained even when the synthesis of ribosomal RNA was inhibited by actinomycin D. The labeled RNA from the nuclear extracts, which contained these RNP-particles, was shown to be heterodisperse RNA.