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DNA replication and progression through the cell cycle.

Publication ,  Journal Article
Dasso, M; Smythe, C; Milarski, K; Kornbluth, S; Newport, JW
Published in: Ciba Foundation symposium
January 1992

Somatic cells possess control mechanisms which monitor DNA replication and assure that it is complete before mitosis is initiated. We have been investigating these mechanisms in Xenopus egg extracts. Using in vitro cycling extracts, which spontaneously alternate between interphase and mitosis, we found that the onset of mitosis is inhibited by the presence of unreplicated DNA, demonstrating that the completion of DNA replication and the initiation of mitosis are coupled in these extracts. As in somatic cells, this coupling is sensitive to caffeine and to okadaic acid. In Xenopus extracts unreplicated DNA increases the tyrosine phosphorylation of p34cdc2, thereby maintaining MPF (mitosis-promoting factor) in an inactive state and preventing the onset of mitosis. The block to mitosis in the presence of unreplicated DNA can be reversed by the addition of bacterially expressed cdc25 protein. The extent of MPF activation by cdc25 protein under these conditions depends on the number of nuclei present. We have developed an assay to examine the rate of tyrosine phosphorylation on p34cdc2. It is increased by unreplicated DNA, in a manner consistent with unreplicated DNA up-regulating the kinase that phosphorylates p34cdc2. We have begun to examine how unreplicated DNA generates the signal that inhibits MPF activation by testing the ability of naked single- and double-stranded DNA templates to inhibit mitosis, and by investigating the role of RCC1, a chromatin-associated protein required for the coupling of DNA replication and mitosis.

Duke Scholars

Published In

Ciba Foundation symposium

DOI

ISSN

0300-5208

Publication Date

January 1992

Volume

170

Start / End Page

161 / 180

Related Subject Headings

  • Protein Tyrosine Phosphatases
  • Maturation-Promoting Factor
  • Fungal Proteins
  • DNA Replication
  • DNA
  • Cell Cycle
  • CDC2 Protein Kinase
  • Animals
 

Citation

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Dasso, M., Smythe, C., Milarski, K., Kornbluth, S., & Newport, J. W. (1992). DNA replication and progression through the cell cycle. Ciba Foundation Symposium, 170, 161–180. https://doi.org/10.1002/9780470514320.ch11
Dasso, M., C. Smythe, K. Milarski, S. Kornbluth, and J. W. Newport. “DNA replication and progression through the cell cycle.Ciba Foundation Symposium 170 (January 1992): 161–80. https://doi.org/10.1002/9780470514320.ch11.
Dasso M, Smythe C, Milarski K, Kornbluth S, Newport JW. DNA replication and progression through the cell cycle. Ciba Foundation symposium. 1992 Jan;170:161–80.
Dasso, M., et al. “DNA replication and progression through the cell cycle.Ciba Foundation Symposium, vol. 170, Jan. 1992, pp. 161–80. Epmc, doi:10.1002/9780470514320.ch11.
Dasso M, Smythe C, Milarski K, Kornbluth S, Newport JW. DNA replication and progression through the cell cycle. Ciba Foundation symposium. 1992 Jan;170:161–180.

Published In

Ciba Foundation symposium

DOI

ISSN

0300-5208

Publication Date

January 1992

Volume

170

Start / End Page

161 / 180

Related Subject Headings

  • Protein Tyrosine Phosphatases
  • Maturation-Promoting Factor
  • Fungal Proteins
  • DNA Replication
  • DNA
  • Cell Cycle
  • CDC2 Protein Kinase
  • Animals