JBC, Vol. 250, Issue 23, 9198-9205, Dec, 1975
Polyanion-induced release of polyribosomes from HeLa cell nuclei
J. A. Goidl, D. Canaani, M. Boublik, H. Weissbach and H. Dickerman
Intact detergent-washed HeLa nuclei contain a population of polyribisomes
that were released by exposure to polyanions such as RNA or poly(U). The
released material appeared by electron microscopic examination to be
particles averaging about 200 to 300 angstroms in diameter. Sedimentation
velocity analysis of the released particles indicated that the particles
had S20,w values of 75 and 110. The particles stimulated amino acid
incorporation in an ascites S-30 or S-100 extract at 2.5 mM Mg2+. Studies
with a variety of antibiotics indicated that these polyribosomes were
capable of elongating but not initiating protein synthesis. Although these
polyribosomes may be of cytoplasmic origin, they appear unique in that
agents thought to disperse chromatin are required for their release from
the nucleus.