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Membrane localization of the kinase which phosphorylates p34cdc2 on threonine 14.

Publication ,  Journal Article
Kornbluth, S; Sebastian, B; Hunter, T; Newport, J
Published in: Molecular biology of the cell
March 1994

The key regulator of entry into mitosis is the serine/threonine kinase p34cdc2. This kinase is regulated both by association with cyclins and by phosphorylation at several sites. Phosphorylation at Tyr 15 and Thr 14 are believed to inhibit the kinase activity of cdc2. In Schizosaccharomyces pombe, the wee1 (and possibly mik1) protein kinase catalyzes phosphorylation of Tyr 15. It is not clear whether these or other, as yet unidentified, protein kinases phosphorylate Thr 14. In this report we show, using extracts of Xenopus eggs, that the Thr 14-directed kinase is tightly membrane associated. Specifically, we have shown that a purified membrane fraction, in the absence of cytoplasm, can promote phosphorylation of cdc2 on both Thr 14 and Tyr 15. In contrast, the cytoplasm can phosphorylate cdc2 only on Tyr 15, suggesting the existence of at least two distinctly localized subpopulations of cdc2 Tyr 15-directed kinases. The membrane-associated Tyr 15 and Thr 14 kinase activities behaved similarly during salt or detergent extraction and were similarly regulated during the cell cycle and by the checkpoint machinery that delays mitosis while DNA is being replicated. This suggests the possibility that a dual-specificity membrane-associated protein kinase may catalyze phosphorylation of both Tyr 15 and Thr 14.

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Published In

Molecular biology of the cell

DOI

EISSN

1939-4586

ISSN

1059-1524

Publication Date

March 1994

Volume

5

Issue

3

Start / End Page

273 / 282

Related Subject Headings

  • Xenopus Proteins
  • Xenopus
  • Threonine
  • Substrate Specificity
  • Schizosaccharomyces pombe Proteins
  • Schizosaccharomyces
  • Protein-Tyrosine Kinases
  • Protein Kinases
  • Phosphorylation
  • Oocytes
 

Citation

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Kornbluth, S., Sebastian, B., Hunter, T., & Newport, J. (1994). Membrane localization of the kinase which phosphorylates p34cdc2 on threonine 14. Molecular Biology of the Cell, 5(3), 273–282. https://doi.org/10.1091/mbc.5.3.273
Kornbluth, S., B. Sebastian, T. Hunter, and J. Newport. “Membrane localization of the kinase which phosphorylates p34cdc2 on threonine 14.Molecular Biology of the Cell 5, no. 3 (March 1994): 273–82. https://doi.org/10.1091/mbc.5.3.273.
Kornbluth S, Sebastian B, Hunter T, Newport J. Membrane localization of the kinase which phosphorylates p34cdc2 on threonine 14. Molecular biology of the cell. 1994 Mar;5(3):273–82.
Kornbluth, S., et al. “Membrane localization of the kinase which phosphorylates p34cdc2 on threonine 14.Molecular Biology of the Cell, vol. 5, no. 3, Mar. 1994, pp. 273–82. Epmc, doi:10.1091/mbc.5.3.273.
Kornbluth S, Sebastian B, Hunter T, Newport J. Membrane localization of the kinase which phosphorylates p34cdc2 on threonine 14. Molecular biology of the cell. 1994 Mar;5(3):273–282.

Published In

Molecular biology of the cell

DOI

EISSN

1939-4586

ISSN

1059-1524

Publication Date

March 1994

Volume

5

Issue

3

Start / End Page

273 / 282

Related Subject Headings

  • Xenopus Proteins
  • Xenopus
  • Threonine
  • Substrate Specificity
  • Schizosaccharomyces pombe Proteins
  • Schizosaccharomyces
  • Protein-Tyrosine Kinases
  • Protein Kinases
  • Phosphorylation
  • Oocytes