C J Goldenberg — Page 2

PubMed1977

In vivo incorporation of ribosomal proteins into HeLa cell ribosomal particles.

Using high salt-washed ribosomal subunits from HeLa cells we detect three ribosomal proteins from the small subunit and five ribosomal proteins from the large subunit that enter ribosomal particles in the absence of ribosome formation (actinomycin D-treated cells); in untreated cells, they enter the ribosomal particles quickly, while the rest of the ribosomal proteins are incorporated gradually. At least two of the large subunit actinomycin D-resistant ribosomal proteins seem to be absent in the 55 S nucleolar ribosomal precursor.

Carbon Radioisotopes↗

PubMed1976

In vivo isotope incorporation patterns into HeLa ribosomal proteins.

When cells were incubated with L-[35S] methionine plus L-[Me-3H] methionine, it was found that at least four ribosomal proteins had 3H/35S ratios higher than the rest of the ribosomal proteins, suggesting that they were methylated. The rate of apparent methylation paralleled the rate of amino acid incorporation. Amino acid incorporation into ribosomal proteins revealed several rapidly labeled components. When 3H-labeled amino acid incorporation was chased for 10 min with an excess of non-radioactive amino acids, several proteins reached at least 60% of the specific activity they showed after 150 min of chase. The time lapse between the onset of 3H-labeled amino acid incorporation and arrival at its plateau appeared to differ among various ribosomal proteins of a subunit, suggesting a heterogeneity in the pools of ribosomal proteins.

HeLa Cells↗