Mdm2 is required for inhibition of Cdk2 activity by p21, thereby contributing to p53-dependent cell cycle arrest.

Luciana E Giono, James J Manfredi
Author Information
  1. Luciana E Giono: Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY 10029, USA. james.manfredi@mssm.edu

Abstract

p53 is extensively posttranslationally modified in response to various types of cellular stress. Such modifications have been implicated in the regulation of p53 protein levels as well as its DNA binding and transcriptional activities. Treatment of cells with doxorubicin causes phosphorylation and acetylation of p53, transcriptional upregulation of p21 and other target genes, and growth arrest. In contrast, downregulation of Mdm2 by a small interfering RNA (siRNA) approach led to increased levels of p53 lacking phosphorylation at serine 15 and acetylation at lysine 382. Levels of binding of p53 to the p21 promoter were comparable following treatment with doxorubicin or Mdm2 siRNA. Moreover, p53 was transcriptionally active and capable of inducing or repressing a variety of its target genes. Surprisingly, p53 upregulated by Mdm2 siRNA had no effect on cell cycle progression. Although comparable in level to that achieved by treatment with the p53 activators actinomycin D and nutlin-3, the increases in p53 and p21 after downregulation of Mdm2 were not sufficient to trigger cell cycle arrest. This version of p21 was capable of interacting with cyclin-dependent kinase 2 (Cdk2) but failed to inhibit its activity. Taken together, these results argue that Mdm2 is needed for full inhibition of Cdk2 activity by p21, thereby positively contributing to p53-dependent cell cycle arrest.

References

  1. J Biol Chem. 1999 Nov 12;274(46):33161-5 [PMID: 10551888]
  2. Science. 2004 Feb 6;303(5659):844-8 [PMID: 14704432]
  3. Oncogene. 2000 Mar 23;19(13):1691-7 [PMID: 10763826]
  4. Oncogene. 2000 May 4;19(19):2312-23 [PMID: 10822382]
  5. J Biol Chem. 2000 Oct 6;275(40):31145-54 [PMID: 10878006]
  6. J Biol Chem. 2000 Oct 13;275(41):31883-90 [PMID: 10906133]
  7. Mol Cell Biol. 2000 Nov;20(22):8458-67 [PMID: 11046142]
  8. Nature. 2000 Nov 16;408(6810):307-10 [PMID: 11099028]
  9. J Biol Chem. 2004 Apr 16;279(16):16000-6 [PMID: 14761977]
  10. Oncogene. 2004 May 27;23(25):4477-87 [PMID: 15064747]
  11. Cell. 1992 Nov 27;71(5):875-86 [PMID: 1423635]
  12. Cell. 1993 Nov 19;75(4):805-16 [PMID: 8242751]
  13. Genes Dev. 1994 Aug 1;8(15):1750-8 [PMID: 7958854]
  14. J Biol Chem. 1995 Mar 10;270(10):5405-11 [PMID: 7534296]
  15. Mol Biol Cell. 1995 Apr;6(4):387-400 [PMID: 7626805]
  16. Cell. 1995 Aug 25;82(4):675-84 [PMID: 7664346]
  17. Nature. 1995 Oct 12;377(6549):552-7 [PMID: 7566157]
  18. Cancer Res. 1995 Nov 15;55(22):5187-90 [PMID: 7585571]
  19. Cancer Res. 1996 Jun 1;56(11):2649-54 [PMID: 8653711]
  20. Nature. 1996 Jul 25;382(6589):325-31 [PMID: 8684460]
  21. Genes Dev. 1997 Aug 15;11(16):2090-100 [PMID: 9284048]
  22. Genes Dev. 1997 Aug 15;11(16):2101-11 [PMID: 9284049]
  23. Cell. 1997 Aug 22;90(4):595-606 [PMID: 9288740]
  24. Mol Cell Biol. 1997 Oct;17(10):5923-34 [PMID: 9315650]
  25. Cell. 1997 Oct 31;91(3):325-34 [PMID: 9363941]
  26. EMBO J. 1998 May 1;17(9):2513-25 [PMID: 9564034]
  27. Mol Cell Biol. 1998 Oct;18(10):5690-8 [PMID: 9742086]
  28. Oncogene. 1998 Sep 24;17(12):1549-56 [PMID: 9794232]
  29. Science. 1998 Nov 20;282(5393):1497-501 [PMID: 9822382]
  30. J Biol Chem. 1998 Dec 4;273(49):33048-53 [PMID: 9830059]
  31. Cell Growth Differ. 1999 Mar;10(3):155-62 [PMID: 10099829]
  32. Biochem J. 1999 Aug 15;342 ( Pt 1):133-41 [PMID: 10432310]
  33. Oncogene. 1999 Jul 29;18(30):4313-25 [PMID: 10439039]
  34. Mol Cell Biol. 1999 Sep;19(9):5872-81 [PMID: 10454534]
  35. Mol Cell. 2004 Dec 3;16(5):725-36 [PMID: 15574328]
  36. J Biol Chem. 2004 Dec 17;279(51):53015-22 [PMID: 15471885]
  37. Curr Cancer Drug Targets. 2005 Feb;5(1):21-6 [PMID: 15720186]
  38. Cancer Res. 2005 Mar 1;65(5):1839-48 [PMID: 15753382]
  39. Mol Cell. 2005 Dec 9;20(5):699-708 [PMID: 16337594]
  40. J Biol Chem. 2006 Jun 23;281(25):16943-50 [PMID: 16624812]
  41. Cell Cycle. 2006 Jun;5(12):1313-9 [PMID: 16775416]
  42. Eur J Biochem. 2001 May;268(10):2764-72 [PMID: 11358490]
  43. Mol Cell Biol. 2001 Aug;21(15):4868-74 [PMID: 11438644]
  44. Clin Cancer Res. 2001 Nov;7(11):3613-24 [PMID: 11705884]
  45. Cancer Res. 2002 Feb 15;62(4):1222-30 [PMID: 11861407]
  46. Int J Oncol. 2002 Apr;20(4):745-52 [PMID: 11894120]
  47. Int J Oncol. 2002 May;20(5):1087-93 [PMID: 11956608]
  48. Mol Med. 2002 Apr;8(4):185-99 [PMID: 12149568]
  49. Prostate. 2003 Feb 15;54(3):194-205 [PMID: 12518324]
  50. Mol Cell Biol. 2003 Aug;23(15):5113-21 [PMID: 12860999]
  51. Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11636-41 [PMID: 13130078]
  52. Mol Cell. 2003 Oct;12(4):1015-27 [PMID: 14580351]
  53. J Biol Chem. 2003 Nov 14;278(46):45946-53 [PMID: 12963717]
  54. EMBO J. 2003 Dec 1;22(23):6365-77 [PMID: 14633995]
  55. Mol Cancer Res. 2003 Dec;1(14):993-1000 [PMID: 14707282]
  56. Mol Cancer Res. 2003 Dec;1(14):1017-26 [PMID: 14707285]
  57. Mol Cell Biol. 2000 May;20(9):3224-33 [PMID: 10757806]

Grants

  1. R01 CA086001/NCI NIH HHS
  2. R01 CA 86001/NCI NIH HHS

MeSH Term

Animals
Antibiotics, Antineoplastic
Cell Cycle
Cell Line
Cell Line, Tumor
Cyclin-Dependent Kinase 2
Cyclin-Dependent Kinase Inhibitor p21
Dactinomycin
Doxorubicin
Humans
Imidazoles
Piperazines
Protein Binding
Protein Processing, Post-Translational
Proto-Oncogene Proteins c-mdm2
RNA, Small Interfering
Response Elements
Tumor Suppressor Protein p53

Chemicals

Antibiotics, Antineoplastic
Cyclin-Dependent Kinase Inhibitor p21
Imidazoles
Piperazines
RNA, Small Interfering
Tumor Suppressor Protein p53
Dactinomycin
nutlin 3
Doxorubicin
Proto-Oncogene Proteins c-mdm2
Cyclin-Dependent Kinase 2

Word Cloud

Created with Highcharts 10.0.0p53p21Mdm2arrestcellcyclesiRNACdk2activitylevelsbindingtranscriptionaldoxorubicinphosphorylationacetylationtargetgenesdownregulationcomparabletreatmentcapableinhibitiontherebycontributingp53-dependentextensivelyposttranslationallymodifiedresponsevarioustypescellularstressmodificationsimplicatedregulationproteinwellDNAactivitiesTreatmentcellscausesupregulationgrowthcontrastsmallinterferingRNAapproachledincreasedlackingserine15lysine382LevelspromoterfollowingMoreovertranscriptionallyactiveinducingrepressingvarietySurprisinglyupregulatedeffectprogressionAlthoughlevelachievedactivatorsactinomycinDnutlin-3increasessufficienttriggerversioninteractingcyclin-dependentkinase2failedinhibitTakentogetherresultsargueneededfullpositivelyrequired

Similar Articles

Cited By