18 S ribosomal RNA is degraded during ribosome maturation in irradiated HeLa cells

Journal Article · Mon May 01 04:00:00 EDT 1989 · Radiation Research; (USA)

DOI:https://doi.org/10.2307/3577447· OSTI ID:5600595

Krolak, J M; McClain, D; Snyder, S L; Fuchs, P; Minton, K W ^[1]

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1. Armed Forces Radiobiology Research Institute, Bethesda, MD (USA)

The effects of ionizing radiation ({sup 137}Cs) on processing of ribosomal RNA (rRNA) were studied by pulse-labeling HeLa S3 cells with ({sup 3}H)uridine immediately prior to irradiation. The 45 S rRNA precursor, and its two major daughter species, 28 and 18 S rRNA, were separated by gel electrophoresis and the extent of radiolabel incorporation into each was determined at various times after irradiation. This approach permitted kinetic analysis of processing of the 45 S rRNA which had been predominantly synthesized (radiolabeled) prior to irradiation. Since they both derive from the same 45 S pre-rRNA transcript, 28 and 18 S rRNA are produced with a stoichiometry of 1:1, as observed in control cells in the present studies. However, within 1 h following 10 Gy an altered stoichiometry of 28 S:18 S rRNA was apparent, reaching 1.6:1 by 5-7 h following irradiation. This alteration was also observed following the higher dose of 20 Gy, but not following exposures of 5 Gy or less. The 18 S portion of the 45 S pre-rRNA is transcribed prior to the 28 S portion. Consequently, an increase in the 28 S/18 S ratio can only be due to degradation of the 18 S species during or after processing. This alteration may represent a response to radiation-induced growth arrest, by reducing the number of newly synthesized ribosomes that would otherwise be required for cell propagation.

• OSTI ID: 5600595
• Journal Information: Radiation Research; (USA), Journal Name: Radiation Research; (USA) Vol. 118:2; ISSN 0033-7587; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
560120* -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALI METAL ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CESIUM 137
CESIUM ISOTOPES
ELECTROPHORESIS
GROWTH
HELA CELLS
HYDROGEN COMPOUNDS
INHIBITION
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MAN
METABOLISM
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PRIMATES
RADIATION EFFECTS
RADIOISOTOPES
RIBOSOMAL RNA
RNA
STOICHIOMETRY
TRACER TECHNIQUES
TRANSCRIPTION
TRITIUM COMPOUNDS
VERTEBRATES
YEARS LIVING RADIOISOTOPES