Mechanisms of p34cdc2 regulation
- PMID: 8441405
- PMCID: PMC359480
- DOI: 10.1128/mcb.13.3.1675-1685.1993
Mechanisms of p34cdc2 regulation
Abstract
The kinase activity of human p34cdc2 is negatively regulated by phosphorylation at Thr-14 and Tyr-15. These residues lie within the putative nucleotide binding domain of p34cdc2. It has been proposed that phosphorylation within this motif ablates the binding of ATP to the active site of p34cdc2, thereby inhibiting p34cdc2 kinase activity (K. Gould and P. Nurse, Nature [London] 342:39-44, 1989). To understand the mechanism of this inactivation, various forms of p34cdc2 were tested for the ability to bind nucleotide. The active site of p34cdc2 was specifically modified by the MgATP analog 5'-p-fluorosulfonylbenzoyladenosine (FSBA). The apparent Km for modification of wild-type, monomeric p34cdc2 was 148 microM FSBA and was not significantly affected by association with cyclin B. Tyrosine-phosphorylated p34cdc2 was modified by FSBA with a slightly higher Km (241 microM FSBA). FSBA modification of both tyrosine-phosphorylated and unphosphorylated p34cdc2 was competitively inhibited by ATP, and half-maximal inhibition in each case occurred at approximately 250 microM ATP. In addition to being negatively regulated by phosphorylation, the kinase activity of p34cdc2 was positively regulated by the cyclin-dependent phosphorylation of Thr-161. Mutation of p34cdc2 at Thr-161 resulted in the formation of an enzymatically inactive p34cdc2/cyclin B complex both in vivo and in vitro. However, mutation of Thr-161 did not significantly affect the ability of p34cdc2 to bind nucleotide (FSBA). Taken together, these results indicate that inhibition of p34cdc2 kinase activity by phosphorylation of Tyr-15 (within the putative ATP binding domain) or by mutation of Thr-161 involves a mechanism other than inhibition of nucleotide binding. We propose instead that the defect resides at the level of catalysis.
Similar articles
-
Role of phosphorylation in p34cdc2 activation: identification of an activating kinase.Mol Biol Cell. 1992 Jan;3(1):13-27. doi: 10.1091/mbc.3.1.13. Mol Biol Cell. 1992. PMID: 1532335 Free PMC article.
-
Inactivation of the p34cdc2-cyclin B complex by the human WEE1 tyrosine kinase.Science. 1992 Sep 25;257(5078):1955-7. doi: 10.1126/science.1384126. Science. 1992. PMID: 1384126
-
Regulation of p34cdc2 protein kinase activity by phosphorylation and cyclin binding.Ciba Found Symp. 1992;170:72-84; discussion 84-96. doi: 10.1002/9780470514320.ch6. Ciba Found Symp. 1992. PMID: 1483352 Review.
-
The cdc2-related protein p40MO15 is the catalytic subunit of a protein kinase that can activate p33cdk2 and p34cdc2.EMBO J. 1993 Aug;12(8):3123-32. doi: 10.1002/j.1460-2075.1993.tb05981.x. EMBO J. 1993. PMID: 8393783 Free PMC article.
-
[The characterization of human cdc2 kinase and CDK2].Yakugaku Zasshi. 1993 Dec;113(12):829-46. doi: 10.1248/yakushi1947.113.12_829. Yakugaku Zasshi. 1993. PMID: 8301538 Review. Japanese.
Cited by
-
MPF localization is controlled by nuclear export.EMBO J. 1998 Jul 15;17(14):4127-38. doi: 10.1093/emboj/17.14.4127. EMBO J. 1998. PMID: 9670027 Free PMC article.
-
Structure-function relationships of the yeast cyclin-dependent kinase Pho85.Mol Cell Biol. 1995 Oct;15(10):5482-91. doi: 10.1128/MCB.15.10.5482. Mol Cell Biol. 1995. PMID: 7565699 Free PMC article.
-
Cyclin A/CDK2 binds directly to E2F-1 and inhibits the DNA-binding activity of E2F-1/DP-1 by phosphorylation.Mol Cell Biol. 1994 Dec;14(12):8420-31. doi: 10.1128/mcb.14.12.8420-8431.1994. Mol Cell Biol. 1994. PMID: 7969176 Free PMC article.
-
E2F4 function in G2: maintaining G2-arrest to prevent mitotic entry with damaged DNA.Cell Cycle. 2007 May 15;6(10):1147-52. doi: 10.4161/cc.6.10.4259. Epub 2007 May 11. Cell Cycle. 2007. PMID: 17507799 Free PMC article. Review.
-
The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment.Biomolecules. 2016 Mar 31;6(2):17. doi: 10.3390/biom6020017. Biomolecules. 2016. PMID: 27043646 Free PMC article.
References
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Molecular Biology Databases
Miscellaneous