Template-specific inhibitor for DNA polymerase isolated from cauliflower inflorescence

Chou, Mei-Yin; Matsumoto, Hiroyuki; Fukata, Hideki; Fukasawa, Hirosuke

doi:10.1016/0005-2787(81)90207-0

Cited by 3 publications

(1 citation statement)

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“…More recently it has been shown that the activity of DNA polymerase a depends on the association with the nuclear skeleton and on inact DNA (Jackson and Cook, 1986b). On the other hand, there is evidence for negative regulatory peptides, which have been found to inhibit DNA polymerase a, in the apex of cauliflower plants (Chou et al, 1981), in Xenopus laevis embryos (Smith et al, 1983), and in stimulated Swiss 3T3 cells (Smith, unpublished data). Dilution kinetics of the crude extracts from cells of different stimulatory conditions are linear with the logarithm of the dilution factor and converge when activity is no longer detectable at the same dilution (1/40) (unpublished results).…”

Section: Discussionmentioning

confidence: 99%

Stimulation of DNA replication by growth factor and hormones in Swiss 3T3 cells: Comparison of the rate of entry into S phase with in vitro DNA synthesis and DNA polymerase α activity

Otto

Smith

Asúa

1988

Journal Cellular Physiology

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An approach to the investigation how growth factors and hormones regulate mammalian cell proliferation is to study the activity of enzymes involved in DNA replication. Quiescent cultures of Swiss mouse 3T3 cells were stimulated with prostaglandin F2 alpha, insulin, and/or hydrocortisone for a time at which less than 50% of the cells had initiated DNA synthesis. Such cells were lysed with a Ca++-containing hypotonic buffer and incubated with a nucleotide mixture including [3H]thymidine-triphosphate for 1 hr at 37 degrees C. The amount of radioactive label incorporated into the trichloroacetic acid (TCA)-precipitate and the percentage of labeled nuclei correlated with the in vivo stimulation. Analysis of radioactively and density-labeled DNA in sucrose and CsC gradients indicated that the incorporation of label reflected semiconservative replication. DNA polymerase activities were assayed in supernatants from whole-cell lysates prepared with a hypotonic buffer not containing Ca++. Using various templates, it was shown that the increase in activity of DNA polymerase alpha correlated with the percentage of cells in S phase upon the different stimulation, while DNA polymerase beta activity after various times of stimulation showed that this activity increased only when cells began to enter S phase, regardless of the combination of growth factor and hormones.

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Section: Discussionmentioning

confidence: 99%