DNA precursor compartmentation in mammalian cells: distribution and rates of equilibration between nucleus and cytoplasm

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5561509

Leeds, J M

A rapid nuclear isolation technique was adapted in order to examine the question of DNA precursor compartmentation in mammalian cells. By using this method a reproducible proportion of the cellular nucleotides remained associated with the isolated nuclei. Examination, at several different cell densities, of exponentially growing HeLa cells showed that the nuclei contained a constant but distinct proportion of each dNTP. The nuclear dATP and dTTP concentrations were equal at all densities examined even though the dTTP pool was 150% of the dATP whole-cell pool. The nuclear portion of the whole-cell pools was roughly equal to the volume occupied by the nucleus. The nuclear-cytoplasmic dNTP pool distribution did not change throughout the cell cycle of synchronized Chinese hamster ovary (CHO) cells. The rates at which either radiolabeled cytidine or deoxycytidine equilibrated with the nuclear and whole-cell dCTP pools of G1 and S phase CHO cells were compared. Experiments comparing the labeling kinetics of /sup 3/H-thymidine in G1, S phase, and exponentially growing cells revealed that the S phase dTTP pool equilibrated with exogenously added thymidine faster than the G1 phase pool. The rate of equilibration in exponentially growing cells appeared to be a combination of that seen in G1 and S phases. A linear rate of /sup 3/H-thymidine incorporation into DNA occurred at the same rate in S phase and exponentially growing cells.

• Research Organization: Oregon State Univ., Corvallis (USA)
• OSTI ID: 5561509
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
AZINES
CELL CONSTITUENTS
CELL CYCLE
CELL NUCLEI
CHO CELLS
COMPARTMENTS
CYTOPLASM
DISTRIBUTION
DNA
HELA CELLS
HETEROCYCLIC COMPOUNDS
LABELLED COMPOUNDS
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RIBOSIDES
SUBCELLULAR DISTRIBUTION
THYMIDINE
TRITIUM COMPOUNDS